21 ms·

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs

by msravi 3y ago

I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted article), that's ~147 kWh of energy storage, and the Tesla can do a rated 650km on a single charge[3]. So that's an efficiency of ~225 Wh/km, which is ~27% of the energy required to run a normal car! It just wouldn't have been possible to run cars on batteries without this efficiency bump. 1. https://chemistry.beloit.edu/edetc/SlideShow/slides/energy/density.html https://chemistry.beloit.edu/edetc/SlideShow/slides/energy/d... 2. https://blog.evbox.com/ev-battery-weight https://blog.evbox.com/ev-battery-weight 3. https://www.caranddriver.com/tesla/model-s https://www.caranddriver.com/tesla/model-s

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TylerE 3y ago
Regen braking will do that. I suspect it’d be a much closer competition at, say, 80mph stead state.
- mrob 3y ago
  Gasoline internal combustion engines run at about 30% efficiency. Diesel does somewhat better at about 40% for car size engines, and about 50% for the really big ones. Electric motors easily exceed 90% efficiency. The EV wins even without regenerative breaking, even accounting for the losses in the batteries.
  - HPsquared 3y ago
    It's somewhat matched if the electricity is generated by combustion. Even then, if the power is generated using an efficient cycle (e.g. CCGT) the EV still tends to come out ahead.
  - _0w8t 3y ago
    40% diesel efficiency is for optimal conditions, like steady cruise on a motorway. For practical driving it is less than 25%. What is also missing here is that it takes 20-30% of energy to refine diesel or gasoline plus there is oil extraction cost. Accounting for that electrical car produces less CO2 when electricity comes from a modern coal plant than a diesel car.
- zelos 3y ago
  There are theoretical maximum efficiencies for thermodynamic cycles in combustion engines. I believe the limit in the diesel cycle is around 40%. Petrol engines are lower still.
- 2rsf 3y ago
  Regen braking is 60-70% efficient, and it also limits your ability to free roll (let go of the gas and let the car use its inertia) for example going downhill or on level highways. Polestar for example recommends to lower the OPD sensitivity on highways to increase efficiency.
oblio 3y ago
That's about the same efficiency as every modern EV. This is not Tesla specific. Electric motors are very efficient, regenerative braking helps, EVs are designed to be super aerodynamic, etc.
- bb123 3y ago
  That is not quite true - you’re right that it is not Tesla specific but many current EVs are far less efficient: https://insideevs.com/news/567087/bev-epa-efficiency-comparison-february2022/amp/ https://insideevs.com/news/567087/bev-epa-efficiency-compari... Particularly German made ones, for some reason.
  - oblio 3y ago
    For US models :-)
- brianwawok 3y ago
  Compare the mpge of different cars. Tesla tends to win even between EVs.
  - toomuchtodo 3y ago
    Engineering first results.
    - oblio 3y ago
      Engineering first? From the company with 1 inch gaps between panels? From the company that had no mechanical handles in the back, so if the electrical stuff stopped working (say, because the battery was on fire), passengers in the back had to finish a puzzle to find out how to get out of the car?
      - brianwawok 3y ago
        My panels look great. i also never look at the outside, because I am inside enjoying it. I guess if you care about panels gap and not performance, go ahead and get a Brokeswagon?
dx034 3y ago
225 Wh/km is even high for most routes and cars. Unless you drive fast on motorways or in cold climate, it's often easy to get to 150 Wh/km (15 kwh/100km as often displayed).
tyfon 3y ago
The 272 Wh/kg is at cell level not pack level which the Tesla weight refers to. In my X has about 92 kWh usable energy when new and it uses around 225 Wh/km at 120 km/h and 170 at 90. The 3 and Y is even more efficient, mostly due to size. But it has a smaller battery, I can get about 69 kWh out of my AWD 3 after losses and it hovers around 170-180 Wh/km at 120 km/h and 130-140 at 90.
onion2k 3y ago
BMW claim that a diesel 3 series will get 61mpg. Volkswagen reckon a Golf 2.0 TDI will do 68mpg. Electric is still significantly better, but you didn't need pick a terrible diesel car as an example.
- znpy 3y ago
  Volkswagen has already been caught cheating (on its emissions) —- not sure I would trust their claims without an independent third party checking on that.
  - gambiting 3y ago
    You can just hop into any diesel Golf/Passat and you'll get 50+ mpg without even trying. No need for third parties.
    - thiagocsf 3y ago
      Mileage != emissions
      - gambiting 3y ago
        Sure but the original post was about mileage, no?
- maccard 3y ago
  Even more confusingly, what the US calls a gallon isn't the same as what other countries call the gallon. It's about a 20% difference.
  - VulgarExigency 3y ago
    Not that confusing, only the US measures fuel in gallons, isn't it? Everyone else just uses liters.
    - 3y ago
leoedin 3y ago
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will come from hydrocarbons - but let's assume it does for ease of comparison sakes). It's much easier to build highly efficient hydrocarbon power stations - typical efficiencies range from 40-60%. So when you look at the headline "efficiency" of an electric car, you need to take that thermodynamic penalty into account first. A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. If you generated the 225 Wh the Tesla needs in even the most efficient combined cycle gas turbine powerplant you'd need 375 Wh. Less - but not nearly as drastic as it first seems. Renewables change the picture though - once you have significant renewable generation the carbon intensity of electricity starts dropping, which means that remote powerplant vs local powerplant argument falls apart. That is when the real power of electric vehicles kicks in - they can take their energy from anywhere.
- antibasilisk 3y ago
  >The big reason for this is thermodynamics. Yes it usually is
- zamnos 3y ago
  > the absolute best theoretical efficiency of this might be 70% I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine. https://physics.stackexchange.com/questions/98966/maximum-theoretical-efficiency-of-internal-combustion-engine https://physics.stackexchange.com/questions/98966/maximum-th...
  - rkangel 3y ago
    It's a different metric but it is generally accepted that F1 cars have reached an overall thermal efficiency of 50%, which is cool. This is taking into account energy recovery from kinetic (regenerative braking) and thermal sources (from the turbo).
tecleandor 3y ago
31mpg is not very efficient. Lots of current diesel engines in Europe are certified at 50+MPG. There's even a Car and Driver test where, with very efficient (and boring) driving you can get 70+MPG out of a Diesel Cruze... https://www.caranddriver.com/news/a15341744/the-prince-of-parsimony-squeezing-max-mileage-from-a-chevy-cruze-diesel/ https://www.caranddriver.com/news/a15341744/the-prince-of-pa...
- bb123 3y ago
  The U.S. uses a Gallon measurement which is about 20% smaller than an international one so you have to factor that in.
  - tecleandor 3y ago
    That Car&Driver article is written in California, so I would have guessed it's US gallons, but now you're making me doubt :D
maccard 3y ago
31mpg is pretty low, even for us gallons. The most sold l car in the UK is (shockingly) the nissan qashqai. They get about 48mpg in imperial gallons which is about 40mpg for the US.
plantain 3y ago
225Wh/km is very high. I see more like 140-160Wh/km driving 80-100km/h on a M3.
- kwhitefoot 3y ago
  At a continuous 80km/h on a level road in the summer I can get down to 160Wh/km even in my 2015 S 70D. I have a friend with a Kia Eniro and he gets similar numbers to you most of the time.
mnw21cam 3y ago
Maths check - 31mpg is 11km/l. (31mi/gal * 1.60934mi/km / 4.54609l/gal) Having said that, my 13-year-old normal sized diesel car does 60mpg in normal use.
- msravi 3y ago
  A US gallon is 3.785 liters...
- 2000UltraDeluxe 3y ago
  There are many cars from 00-05 and with emission levels that are relatively low; if one is to make a somewhat absurd suggestion to prove a point, I'd suggest many smaller petrol and dieselbcars would be cleaner than an EV _if_ the EV was charged with 100% coal power. Luckily, most people don't charge their teslas with coal power.
- xxs 3y ago
  Yeah but nobody actually uses kilometers per liter.
5ersi 3y ago
Compare that to liquid hydrogen at 33000 Wh/kg. The problem is that at that point liquid hydrogen already spent 70% of the energy stored in it (80% efficiency of electrolysis * 40% liquefying efficiency) .
qikInNdOutReply 3y ago
So, how about we apologize in public to the engineers who said no to radar, cause boy oh boy would that one have eaten battery, which would need additional batteries, which would have torrn into the car rocket equation ?
john61 3y ago
What about charging efficiency?
- 2rsf 3y ago
  DC is better then AC and both depends on how much the battery is already charged, temperature of the battery, the infrastructure (charging cables for example). The range is somewhere from low 80's for low amperage AC charging on cold weather using a low quality granny charger cable to high 90's for a warm battery on a dedicated high power DC charger. This of course doesn't include losses in transmission from the power station and in electricity production.
  - xxs 3y ago
    Charging goes like this: - AC converted to DC (with power factor correction, usually means AC stepped up 1st) - DC converted back to AC (but higher voltage) and MUCH higher frequency - AC transformed to lower AC voltage (still higher frequence) - AC rectified to DC (filtered and stabilized), DC voltage lower If there is DC, the very 1st part can be omitted.
    - 2rsf 3y ago
      Wait! what? why? as part of the DC to DC conversion? how does it affect efficiency?
    - cyberax 3y ago
      That's not true. Tesla works like this: 1. You have a high-voltage DC bus that is basically connected to all battery modules. Modules have individual BMS modules and can connect/disconnect to that bus. 2. If you're doing fast charging, the charger connects to that bus directly (you can hear contactors closing), matches the voltage and pushes the current. 3. If you're doing AC slow charging, the charging module on the Tesla simply boosts the voltage to the bus level via a PWM-based power supply. That's it. A pretty simple system.
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peoplefromibiza 3y ago
> A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg That's not very good, my LPG car runs on average around 25km/l and around 30km/l on gas, albeit being a 10 years old model. Modern diesel cars run on average at over 20km/l, the Citroen C3 does ~30km/l.
littlestymaar 3y ago
> which is ~27% of the energy required to run a normal car! This is because you're not comparing the same things: going from thermal energy to mechanical energy has a much lower efficiency than going from electricity to mechanical energy. But that electricity has to come from somewhere, and most of the losses happen at the electricity generation place instead of in the car. > It just wouldn't have been possible to run cars on batteries without this efficiency bump. Electric motor have always been far more efficient than ICE ones, even in the 19th. In fact, the difference was even bigger, because combustion engine sucked hard back then, whereas electric engine didn't make as much progress as combustion engine ones (that doesn't mean that they didn't make progress, they did, but there's far less of a difference between an electric engine of 1920 and the one in a Tesla, than between an ICE engine then and now).
- cyberax 3y ago
  Sorry, but this is BS. Modern electric engines in Tesla Model 3 use high-speed power transistors to precisely modulate the magnetic field. Back in 1920 all you could do was a collector plate with brushes. The difference is like the difference between carburetor engines and direct fuel injection.
  - littlestymaar 3y ago
    > Back in 1920 all you could do was a collector plate with brushes. And these are still more efficient than most combustion engines *today*, that's exactly my point.
gambiting 3y ago
How the hell a Chevy Cruze gets 31mpg with a diesel??? A VW Passat TDI will easily get 60+ imperial MPG, I've had it get close to 70 on long runs(that's 50 and 58 American MPG respectively). Are American diesels this inefficient?? Looking at pictures online the Chevy cruze doesn't seem like a bigger/heavier car than a Passat, so what gives??
- kube-system 3y ago
  I think they were citing city fuel economy. Some trims of the Cruise did get 50+ US MPG highway (when it was still sold here) Although I completely forgot it existed. There are not many diesel passenger cars on US roads. Diesel is consistently more expensive than petrol here.
- dahwolf 3y ago
  Here in the Netherlands, we'd translate 31mpg to "1 per 11". One can drive 11km on 1L of fuel. 1 per 11 is a joke. It's associated with heavy petrol cars from the 80s and 90s, before anybody even attempted efficiency. Even my 15 year old diesel car had an efficiency of 1/22. Adjust you driving style and I'd get 1/25. Range: 1000km, with an ordinary sized tank. It seems Americans haven't even started with efficiency, quite likely because there was no pressure to do so due to low fuel prices. Not in their homes, not in their cars, not anywhere.
  - weberer 3y ago
    What's with these weird, grandiose generalizations I've been seeing about America on this site, based on single data points? Do you realize that other brands and models exist in the USA? Do you realize Tesla is and American company? Did you even check look into Chevy Cruze's mileage? Here's a guy getting 70mpg in a Chevy Cruze by driving 55mph on the highway. That's 30km/l. https://www.caranddriver.com/news/a15341744/the-prince-of-parsimony-squeezing-max-mileage-from-a-chevy-cruze-diesel/ https://www.caranddriver.com/news/a15341744/the-prince-of-pa...
    - gambiting 3y ago
mvanbaak 3y ago
> 13.2 km/l For diesel, this is really really bad. Most gasoline cars will run more economic than this, let alone diesel. If your diesel runs less then 17 to 18 km/l something is wrong. (my opinion is based on how things are in .nl, other parts of the world can and will be different of course)
- manuelmoreale 3y ago
  Yeah 13.2km/l for a diesel is quite terrible if we’re talking regular cars. I personally average in the 20 to 25 range with mine.
rlue 3y ago
Maybe I missed something, but seems very weird to compare kg of diesel fuel to kg of battery. The posted article's figure of 272Wh/kg is for battery capacity, not energy yield from source fuel.
bertil 3y ago
During the introduction to a speech by J. B. Straubel, the presenter said his mentor’s motivations were that 1% of the energy in the gas tank was moving the passenger, 12% the car, and the rest was lost. We should measure efficiency based on that number.
adverbly 3y ago
12700 doesn't include all the diesel engine parts. Also, electric motors much more efficient. Still, your point stands.
xxs 3y ago
>runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg The measurements outside North America are reciprocal, e.g. 7.7L/100km (which is awfully inefficient for a diesel, normally it should be around 5L) So converting gallon to liter, and mile to kilometer is the wrong way to present it. As for the efficiency in general - of course electric engines have a very high efficiency (in the 90s), unlikely diesel which can barely hit 35%.
- mabbo 3y ago
  This delightful article presents a fun reason why the L/100km unit is better: https://what-if.xkcd.com/11/ https://what-if.xkcd.com/11/
chrismorgan 3y ago
> 225 Wh/km Meanwhile, fairly common cycling parameters lead to well under 10 Wh/km at comfortable cruising speeds, and with things like velomobiles you kinda start around 5 Wh/km, and 3 Wh/km is possible without significantly compromising the practicality of the vehicle. Sure, sure, lower speeds, lower cargo capacity, lower safety, &c. &c. But it’s still a useful comparison to contemplate, especially when considering the nascent category Lightweight Electric Vehicles, which in its most interesting form isn’t far off “ebike minus pedals”. Cars are still pretty power-inefficient as a general concept.
twobitshifter 3y ago
Something you left out here is that the full capacity of the battery can’t be used. Tesla uses more of the battery than other manufacturers, which gives them a higher range per rated watt hour. On top of that, they have more efficient components. When you compare a model S to a lightweight Carbon Fiber BMW i3, with a much smaller pack, you’ll see that the modelS still squeezes out a higher mpgE rating. https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=46207&id=41055 https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=46207&...
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clouddrover 3y ago
> and the Tesla Model S can do a rated 650km on a single charge It's better to use real world highway range which is 300 miles (482 km) in a Model S: https://insideevs.com/reviews/443791/ev-range-test-results/ https://insideevs.com/reviews/443791/ev-range-test-results/
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ed_balls 3y ago
> ~27% of the energy required to run a normal car It would be slightly worse in colder climates. I wish car manufactures would allow for easy installation for range extenders in the front trunk. I'd be a great source of heat for the heat pump. Range anxiety would be gone. No carbon tax since it would be an aftermarket solution. It seems Mazda MX-30 r-ev is the only thing you can buy.
- kwhitefoot 3y ago
  > Range anxiety would be gone. Range anxiety is an affliction more common among those who do not drive an EV than those who do.
  - mdp2021 3y ago
    > is an affliction more common among That is a tautology... "Those who weigh the downside more remain in the alternative option." What did you want to mean?
    - vel0city 3y ago
      Their point was that a number of people who have range anxiety are those who haven't actually looked at what the impact of changing to an EV would actually be. Which, for a lot of people, wouldn't be nearly as much as they would think. A lot of people with range anxiety probably use an EV with little to no impact in their driving habits other than plugging in when they get home. But they're so concerned with "what if's" that rarely ever come up in their lives. "But what if I suddenly need to drive across the country taking only back country roads and avoiding all highways across the furthest north roads in the coldest of winter?? Can't do that in an EV!" The most common reactions I get to people asking about my EV are along the lines of "But how do you charge it? Don't you have to wait at public chargers all the time? It must be so challenging driving an EV with so many broken chargers all the time! You must have to wait so long all the time for all that charging, its so slow!" Which is quite strange, because the vast majority of charging sessions most EVs would probably experience are plugging in at their home entirely negating these concerns. For a lot of those people asking me those questions (often friends and family), I know they'd be able to replace a car with an EV and have only positive impacts other than the costs of buying a new car (something they do on some schedule regularly). But the talking heads on the TV tell them EVs == slow, unreliable, expensive charging so clearly all EV owners must be dealing with largely unavailable, unreliable, expensive, slow charging all the time. When in reality I spend more time pumping gas in my ICE than I do waiting on my EV to charge, I've encountered more broken gas pumps than charging dispensers in the last year, and it costs me almost 10x less in energy cost than my ICE per mile.
jillesvangurp 3y ago
Not only that. The more important conclusion is that actually ICE cars are stupendously inefficient. All that extra energy ICE cars carry isn't actually being put to use very well. They don't have more powerful engines. They don't have more torque. They don't have more acceleration. And even their range isn't that much better. You can of course get models that take something like 100+ liters of petrol. But the per liter performance only gets worse if you do that (heavier cars are less efficient). The reality is that yes, fuel is very energy dense but sadly most of that isn't transformed into motion when you use it. You are instead making lots of noise (vibrations) and heat. Both are actually bad for your car. So, you use most of the energy to wear out your car faster. The more powerful the car, the less efficient they are. And the faster they break down.
vivegi 3y ago
I have a fundamental question though. Will EVs (Li battery based) achieve the holy grail of IC engine replacement? Earth's Lithium deposits.................. 88,000,000,000 Kilograms [2], [3] @25% Viable for mining.................... 22,000,000,000 Kilograms [2], [3] Tesla S battery weight.................... 540 Kilograms per car [4] Lithium weight per Tesla S battery........ 63 Kilograms per battery [4] Max Tesla S (global) production possible.. 349,206,349 units (See Edit below) Number of automobiles running in the USA.. 102,000,000 units [1] Number of automobiles running in the World 1,500,000,000 units [5] So, even if we theoretically assume that the earth's entire known Li reserves are used for EV usage, we cannot replace more than 25% of the currently running cars in the world. So, we have a bigger problem ahead of us (over the next decade) that will act as an opposing force against EV penetration and replacement of the IC engine. Solutions possibly lie in exploring other battery chemistries while improving the efficiency of Li extraction. Edit: As some of the comments below point out, the Li content in a Tesla Model S battery is approx. 63 Kg. That makes the Max Tesla S (production) possible to 349 million units. So, in theory, one could replace all IC engines in automobiles plying in the USA. That then leaves the rest of the world. So, the problem still remains. [1]: https://www.fhwa.dot.gov/policyinformation/statistics/2021/mv1.cfm https://www.fhwa.dot.gov/policyinformation/statistics/2021/m... [2]: https://www.popularmechanics.com/science/energy/a42417327/lithium-supply-batteries-electric-vehicles/ https://www.popularmechanics.com/science/energy/a42417327/li... [3]: https://www.usgs.gov/centers/national-minerals-information-center/lithium-statistics-and-information https://www.usgs.gov/centers/national-minerals-information-c... [4]: https://blog.evbox.com/ev-battery-weight https://blog.evbox.com/ev-battery-weight [5]: https://www.weforum.org/agenda/2016/04/the-number-of-cars-worldwide-is-set-to-double-by-2040 https://www.weforum.org/agenda/2016/04/the-number-of-cars-wo...
- tryptophan 3y ago
  Known Earth's Lithium deposits =/= Earth's Lithium Deposits
  - epistasis 3y ago
    And in fact this number changed by large amounts in the last decade, even before the current boom of the 2020s. Remember peak oil, which was a big panic of some in the 2000s? It turns out that peak production didn't happen overall, but if you look at the original set of "known resources", the peak oil predictions were spot on. Yet we didn't experience huge oil supply shortages because huge expenditures into new fracking tech enables far more resources to be accessed. We have always loved in a complete abundance of lithium, so we never bothered to look for more resources. Now that we need more, we will find it. It's not a particularly rare element.
codethief 3y ago
> 31mpg mpg = miles per gallon
steveBK123 3y ago
Relative efficiencies also explain why city/highway efficiency is inverted between EV & ICE. Gasoline is rather energy dense, but the ICE is rather wasteful. There is a certain base load of energy being generated by an ICE engine, regardless of if you are moving or how slow you go. This is why carmakers experimented with things like rapid stop/start engines, regen batteries&motors, etc. ICE becomes more efficient as you reach highway speeds, which is why highway mpg is better than city mpg. Batteries by contrast are not very energy dense, while EV motors are extremely efficient. The only energy being consumed is that which is needed to move the car, plus fight rolling & wind resistance, and power AC/heat. Wind resistance increases with the square of speed. EVs as a result are most efficient at low speed, and at highway speeds become noticeably less efficient as you go from 55->65->75mph. This is also why running AC/heat has a noticeable impact on range in EVs.
- dahfizz 3y ago
  Meh, the only reason EVs are more efficient in the city is because of regen braking. An ICE car traveling at a constant 30mph is going to get much better fuel economy than an ICE car traveling at a constant 75mph. The difference is that <=30mph roads usually have a lot of stop-and-go.
  - steveBK123 3y ago
    ICE efficiency also more driven by RPM & therefore where you are in the gears. So ICE designers have decisions to make about which speeds to optimize for. ICE peak efficiency tends to be more around 45mph than 30mph. But yes, the less you brake in an ICE, the more efficient. Hybrids give you a bit of the ICE range/highway efficiency with the EV city driving efficiency, with the added complexity of having ICE & EV under one hood.
    - rootusrootus 3y ago
      A modern 8-10 speed automatic transmission can easily put the engine at or near the ideal consumption RPM whether it's 30 mph or 80 mph. If we really cared about efficiency, we'd have smaller motors. Throttling decreases efficiency, so the best mileage is going to be cruising at WOT (naively assuming no fuel mixture enrichment, which isn't always true). A classic example of this strategy is an old Geo Metro. Light, tiny motor, and barely capable of maintaining highway speed using peak horsepower.
jvanderbot 3y ago
in practice, I get 400Wh/mi. So, 50%?
osigurdson 3y ago
This is definitely not an apples-to-apples comparison. With an EV the ball is already at the top of the hill and merely needs to be rolled down, with an ICE car, the ball has to be pushed up the hill first. The power plant does all of the heavy lifting for the EV. Not a mark against EVs of course - it kind of just makes sense. I'm sure future generations will laugh that every vehicle used to have its own on-board power generation facility. It's too bad the dumb power-plant-under-hood way is still so much cheaper than the EV approach of course.
- dd36 3y ago
  It’s not cheaper.
  - osigurdson 3y ago
    If EVs were cheaper, everyone would own one.
    - dd36 3y ago
      Only those buying news cars would own one. And that is beginning to happen.
Keyframe 3y ago
For a normal, new car, anything above 6l/100km for that size of a car (and usually around 5) is something's wrong with the car. That's more than twice the efficiency of described one from 1976.
thebigspacefuck 3y ago
Isn’t this what the MPGe rating tells you?
strangescript 3y ago
Its almost like electric cars are cleaner, more efficient and better for the environment. Telsa's are god tier level of engineering under the hood. (Maybe not so much fit and finish). The only reason the gov't isn't buying these for everyone is because Tesla disrupted deeply entrenched companies and people don't like Elon.
timbit42 3y ago
The Aptera gets 1000 miles on a 100 kWh battery. Porsche Taycan: 2 miles per kWh Tesla Model 3: 5 miles per kWh Lightyear Zero: 7 miles per kWh Aptera: 10 miles per kWh Source: https://www.youtube.com/watch?v=mpiH-Y-HOvE https://www.youtube.com/watch?v=mpiH-Y-HOvE
- vel0city 3y ago
  > The Aptera gets 1000 miles on a 100 kWh battery. The Aptera gets 0 miles on a 0 kWh battery because they've shipped 0 cars, right? Can I go buy one and drive it today?
  - timbit42 3y ago
    What makes you think it won't get to market? Sure, they failed in the past but they have the money now and they've certainly shown they won't give up.
    - vel0city 3y ago
      > The Aptera gets 1000 miles on a 100 kWh battery. Gets, as in present tense. A theoretical car made sometime in the future shouldn't use present tense terminology. No consumer on the road today is getting 1,000mi on a 100kWh battery in an Aptera. If Aptera manages to actually ship cars, then the word "gets" is accurate. > What makes you think it won't get to market? See: > Sure, they failed in the past Building cars has extremely high barriers to entry. Getting things approved costs tons of money. Spinning up factories is no small challenge. Actually making more than one or two cars is incredibly challenging. Meanwhile, in order to spread those costs out you'll hopefully want to make a lot of them otherwise a good chunk of your value proposition goes away as the costs for the car would quickly get out of hand. Then comes the challenges of actually selling them at any volume. I legally can't buy one in my state if they don't create a franchise dealer network. Its hard to get shoppers to compare your vehicles if you don't have a way for them to actually buy the cars. Tesla manages because they spent a ton on "galleries", they were the only real EV option for a while, and have massive brand presence. Ask any random average car buyer if they've thought of buying an Tesla, and they'll probably have an opinion. Ask anyone if they've thought of buying an Aptera, and they'll probably have no clue what you're talking about. If Aptera manages to actually make some cars, that's great! Even better if they manage to sell them for profit. Its good to have more competition. But I'm not holding my breath.
alliao 3y ago
model Y consistently do 150Wh/km which is just nuts... one thing with petrol chemical too is it's not carrying all the energy with it, the oxygen came from atmosphere while EV is carrying the entire energy required to run with itself..

by msravi 3y ago

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TylerE 3y ago

Regen braking will do that. I suspect it’d be a much closer competition at, say, 80mph stead state.

mrob 3y ago
Gasoline internal combustion engines run at about 30% efficiency. Diesel does somewhat better at about 40% for car size engines, and about 50% for the really big ones. Electric motors easily exceed 90% efficiency. The EV wins even without regenerative breaking, even accounting for the losses in the batteries.
- HPsquared 3y ago
  It's somewhat matched if the electricity is generated by combustion. Even then, if the power is generated using an efficient cycle (e.g. CCGT) the EV still tends to come out ahead.
- _0w8t 3y ago
  40% diesel efficiency is for optimal conditions, like steady cruise on a motorway. For practical driving it is less than 25%. What is also missing here is that it takes 20-30% of energy to refine diesel or gasoline plus there is oil extraction cost. Accounting for that electrical car produces less CO2 when electricity comes from a modern coal plant than a diesel car.
zelos 3y ago
There are theoretical maximum efficiencies for thermodynamic cycles in combustion engines. I believe the limit in the diesel cycle is around 40%. Petrol engines are lower still.
2rsf 3y ago
Regen braking is 60-70% efficient, and it also limits your ability to free roll (let go of the gas and let the car use its inertia) for example going downhill or on level highways. Polestar for example recommends to lower the OPD sensitivity on highways to increase efficiency.

oblio 3y ago

That's about the same efficiency as every modern EV. This is not Tesla specific. Electric motors are very efficient, regenerative braking helps, EVs are designed to be super aerodynamic, etc.

bb123 3y ago
That is not quite true - you’re right that it is not Tesla specific but many current EVs are far less efficient: https://insideevs.com/news/567087/bev-epa-efficiency-comparison-february2022/amp/ https://insideevs.com/news/567087/bev-epa-efficiency-compari... Particularly German made ones, for some reason.
- oblio 3y ago
  For US models :-)
brianwawok 3y ago
Compare the mpge of different cars. Tesla tends to win even between EVs.
- toomuchtodo 3y ago
  Engineering first results.
  - oblio 3y ago
    Engineering first? From the company with 1 inch gaps between panels? From the company that had no mechanical handles in the back, so if the electrical stuff stopped working (say, because the battery was on fire), passengers in the back had to finish a puzzle to find out how to get out of the car?
    - brianwawok 3y ago
      My panels look great. i also never look at the outside, because I am inside enjoying it. I guess if you care about panels gap and not performance, go ahead and get a Brokeswagon?

dx034 3y ago

225 Wh/km is even high for most routes and cars. Unless you drive fast on motorways or in cold climate, it's often easy to get to 150 Wh/km (15 kwh/100km as often displayed).

tyfon 3y ago

The 272 Wh/kg is at cell level not pack level which the Tesla weight refers to. In my X has about 92 kWh usable energy when new and it uses around 225 Wh/km at 120 km/h and 170 at 90. The 3 and Y is even more efficient, mostly due to size. But it has a smaller battery, I can get about 69 kWh out of my AWD 3 after losses and it hovers around 170-180 Wh/km at 120 km/h and 130-140 at 90.

onion2k 3y ago

BMW claim that a diesel 3 series will get 61mpg. Volkswagen reckon a Golf 2.0 TDI will do 68mpg. Electric is still significantly better, but you didn't need pick a terrible diesel car as an example.

znpy 3y ago
Volkswagen has already been caught cheating (on its emissions) —- not sure I would trust their claims without an independent third party checking on that.
- gambiting 3y ago
  You can just hop into any diesel Golf/Passat and you'll get 50+ mpg without even trying. No need for third parties.
  - thiagocsf 3y ago
    Mileage != emissions
    - gambiting 3y ago
      Sure but the original post was about mileage, no?
maccard 3y ago
Even more confusingly, what the US calls a gallon isn't the same as what other countries call the gallon. It's about a 20% difference.
- VulgarExigency 3y ago
  Not that confusing, only the US measures fuel in gallons, isn't it? Everyone else just uses liters.
  - 3y ago

leoedin 3y ago

The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will come from hydrocarbons - but let's assume it does for ease of comparison sakes). It's much easier to build highly efficient hydrocarbon power stations - typical efficiencies range from 40-60%. So when you look at the headline "efficiency" of an electric car, you need to take that thermodynamic penalty into account first. A modern series hybrid like a Toyota Prius is effectively an electric vehicle and a gas generator (which means it has the same efficiency gains due to regenerative braking). That gets 52 mpg, which is about 493 Wh/km. If you generated the 225 Wh the Tesla needs in even the most efficient combined cycle gas turbine powerplant you'd need 375 Wh. Less - but not nearly as drastic as it first seems. Renewables change the picture though - once you have significant renewable generation the carbon intensity of electricity starts dropping, which means that remote powerplant vs local powerplant argument falls apart. That is when the real power of electric vehicles kicks in - they can take their energy from anywhere.

antibasilisk 3y ago
>The big reason for this is thermodynamics. Yes it usually is
zamnos 3y ago
> the absolute best theoretical efficiency of this might be 70% I fell down a rabbit hole and found this link, which gives 46% for the theoretical limit for the efficiency of the internal combustion engine. https://physics.stackexchange.com/questions/98966/maximum-theoretical-efficiency-of-internal-combustion-engine https://physics.stackexchange.com/questions/98966/maximum-th...
- rkangel 3y ago
  It's a different metric but it is generally accepted that F1 cars have reached an overall thermal efficiency of 50%, which is cool. This is taking into account energy recovery from kinetic (regenerative braking) and thermal sources (from the turbo).

tecleandor 3y ago

31mpg is not very efficient. Lots of current diesel engines in Europe are certified at 50+MPG. There's even a Car and Driver test where, with very efficient (and boring) driving you can get 70+MPG out of a Diesel Cruze... https://www.caranddriver.com/news/a15341744/the-prince-of-parsimony-squeezing-max-mileage-from-a-chevy-cruze-diesel/ https://www.caranddriver.com/news/a15341744/the-prince-of-pa...

bb123 3y ago
The U.S. uses a Gallon measurement which is about 20% smaller than an international one so you have to factor that in.
- tecleandor 3y ago
  That Car&Driver article is written in California, so I would have guessed it's US gallons, but now you're making me doubt :D

maccard 3y ago

31mpg is pretty low, even for us gallons. The most sold l car in the UK is (shockingly) the nissan qashqai. They get about 48mpg in imperial gallons which is about 40mpg for the US.

plantain 3y ago

225Wh/km is very high. I see more like 140-160Wh/km driving 80-100km/h on a M3.

kwhitefoot 3y ago
At a continuous 80km/h on a level road in the summer I can get down to 160Wh/km even in my 2015 S 70D. I have a friend with a Kia Eniro and he gets similar numbers to you most of the time.

mnw21cam 3y ago

Maths check - 31mpg is 11km/l. (31mi/gal * 1.60934mi/km / 4.54609l/gal) Having said that, my 13-year-old normal sized diesel car does 60mpg in normal use.

msravi 3y ago
A US gallon is 3.785 liters...
2000UltraDeluxe 3y ago
There are many cars from 00-05 and with emission levels that are relatively low; if one is to make a somewhat absurd suggestion to prove a point, I'd suggest many smaller petrol and dieselbcars would be cleaner than an EV _if_ the EV was charged with 100% coal power. Luckily, most people don't charge their teslas with coal power.
xxs 3y ago
Yeah but nobody actually uses kilometers per liter.

5ersi 3y ago

Compare that to liquid hydrogen at 33000 Wh/kg. The problem is that at that point liquid hydrogen already spent 70% of the energy stored in it (80% efficiency of electrolysis * 40% liquefying efficiency) .

qikInNdOutReply 3y ago

So, how about we apologize in public to the engineers who said no to radar, cause boy oh boy would that one have eaten battery, which would need additional batteries, which would have torrn into the car rocket equation ?

john61 3y ago

What about charging efficiency?

2rsf 3y ago
DC is better then AC and both depends on how much the battery is already charged, temperature of the battery, the infrastructure (charging cables for example). The range is somewhere from low 80's for low amperage AC charging on cold weather using a low quality granny charger cable to high 90's for a warm battery on a dedicated high power DC charger. This of course doesn't include losses in transmission from the power station and in electricity production.
- xxs 3y ago
  Charging goes like this: - AC converted to DC (with power factor correction, usually means AC stepped up 1st) - DC converted back to AC (but higher voltage) and MUCH higher frequency - AC transformed to lower AC voltage (still higher frequence) - AC rectified to DC (filtered and stabilized), DC voltage lower If there is DC, the very 1st part can be omitted.
  - 2rsf 3y ago
    Wait! what? why? as part of the DC to DC conversion? how does it affect efficiency?
  - cyberax 3y ago
    That's not true. Tesla works like this: 1. You have a high-voltage DC bus that is basically connected to all battery modules. Modules have individual BMS modules and can connect/disconnect to that bus. 2. If you're doing fast charging, the charger connects to that bus directly (you can hear contactors closing), matches the voltage and pushes the current. 3. If you're doing AC slow charging, the charging module on the Tesla simply boosts the voltage to the bus level via a PWM-based power supply. That's it. A pretty simple system.

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peoplefromibiza 3y ago

> A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg That's not very good, my LPG car runs on average around 25km/l and around 30km/l on gas, albeit being a 10 years old model. Modern diesel cars run on average at over 20km/l, the Citroen C3 does ~30km/l.

littlestymaar 3y ago

> which is ~27% of the energy required to run a normal car! This is because you're not comparing the same things: going from thermal energy to mechanical energy has a much lower efficiency than going from electricity to mechanical energy. But that electricity has to come from somewhere, and most of the losses happen at the electricity generation place instead of in the car. > It just wouldn't have been possible to run cars on batteries without this efficiency bump. Electric motor have always been far more efficient than ICE ones, even in the 19th. In fact, the difference was even bigger, because combustion engine sucked hard back then, whereas electric engine didn't make as much progress as combustion engine ones (that doesn't mean that they didn't make progress, they did, but there's far less of a difference between an electric engine of 1920 and the one in a Tesla, than between an ICE engine then and now).

cyberax 3y ago
Sorry, but this is BS. Modern electric engines in Tesla Model 3 use high-speed power transistors to precisely modulate the magnetic field. Back in 1920 all you could do was a collector plate with brushes. The difference is like the difference between carburetor engines and direct fuel injection.
- littlestymaar 3y ago
  > Back in 1920 all you could do was a collector plate with brushes. And these are still more efficient than most combustion engines *today*, that's exactly my point.

gambiting 3y ago

How the hell a Chevy Cruze gets 31mpg with a diesel??? A VW Passat TDI will easily get 60+ imperial MPG, I've had it get close to 70 on long runs(that's 50 and 58 American MPG respectively). Are American diesels this inefficient?? Looking at pictures online the Chevy cruze doesn't seem like a bigger/heavier car than a Passat, so what gives??

kube-system 3y ago
I think they were citing city fuel economy. Some trims of the Cruise did get 50+ US MPG highway (when it was still sold here) Although I completely forgot it existed. There are not many diesel passenger cars on US roads. Diesel is consistently more expensive than petrol here.
dahwolf 3y ago
Here in the Netherlands, we'd translate 31mpg to "1 per 11". One can drive 11km on 1L of fuel. 1 per 11 is a joke. It's associated with heavy petrol cars from the 80s and 90s, before anybody even attempted efficiency. Even my 15 year old diesel car had an efficiency of 1/22. Adjust you driving style and I'd get 1/25. Range: 1000km, with an ordinary sized tank. It seems Americans haven't even started with efficiency, quite likely because there was no pressure to do so due to low fuel prices. Not in their homes, not in their cars, not anywhere.
- weberer 3y ago
  What's with these weird, grandiose generalizations I've been seeing about America on this site, based on single data points? Do you realize that other brands and models exist in the USA? Do you realize Tesla is and American company? Did you even check look into Chevy Cruze's mileage? Here's a guy getting 70mpg in a Chevy Cruze by driving 55mph on the highway. That's 30km/l. https://www.caranddriver.com/news/a15341744/the-prince-of-parsimony-squeezing-max-mileage-from-a-chevy-cruze-diesel/ https://www.caranddriver.com/news/a15341744/the-prince-of-pa...
  - gambiting 3y ago

mvanbaak 3y ago

> 13.2 km/l For diesel, this is really really bad. Most gasoline cars will run more economic than this, let alone diesel. If your diesel runs less then 17 to 18 km/l something is wrong. (my opinion is based on how things are in .nl, other parts of the world can and will be different of course)

manuelmoreale 3y ago
Yeah 13.2km/l for a diesel is quite terrible if we’re talking regular cars. I personally average in the 20 to 25 range with mine.

rlue 3y ago

Maybe I missed something, but seems very weird to compare kg of diesel fuel to kg of battery. The posted article's figure of 272Wh/kg is for battery capacity, not energy yield from source fuel.

bertil 3y ago

During the introduction to a speech by J. B. Straubel, the presenter said his mentor’s motivations were that 1% of the energy in the gas tank was moving the passenger, 12% the car, and the rest was lost. We should measure efficiency based on that number.

adverbly 3y ago

12700 doesn't include all the diesel engine parts. Also, electric motors much more efficient. Still, your point stands.

xxs 3y ago

>runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg The measurements outside North America are reciprocal, e.g. 7.7L/100km (which is awfully inefficient for a diesel, normally it should be around 5L) So converting gallon to liter, and mile to kilometer is the wrong way to present it. As for the efficiency in general - of course electric engines have a very high efficiency (in the 90s), unlikely diesel which can barely hit 35%.

mabbo 3y ago
This delightful article presents a fun reason why the L/100km unit is better: https://what-if.xkcd.com/11/ https://what-if.xkcd.com/11/

chrismorgan 3y ago

> 225 Wh/km Meanwhile, fairly common cycling parameters lead to well under 10 Wh/km at comfortable cruising speeds, and with things like velomobiles you kinda start around 5 Wh/km, and 3 Wh/km is possible without significantly compromising the practicality of the vehicle. Sure, sure, lower speeds, lower cargo capacity, lower safety, &c. &c. But it’s still a useful comparison to contemplate, especially when considering the nascent category Lightweight Electric Vehicles, which in its most interesting form isn’t far off “ebike minus pedals”. Cars are still pretty power-inefficient as a general concept.

twobitshifter 3y ago

Something you left out here is that the full capacity of the battery can’t be used. Tesla uses more of the battery than other manufacturers, which gives them a higher range per rated watt hour. On top of that, they have more efficient components. When you compare a model S to a lightweight Carbon Fiber BMW i3, with a much smaller pack, you’ll see that the modelS still squeezes out a higher mpgE rating. https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=46207&id=41055 https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=46207&...

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clouddrover 3y ago

> and the Tesla Model S can do a rated 650km on a single charge It's better to use real world highway range which is 300 miles (482 km) in a Model S: https://insideevs.com/reviews/443791/ev-range-test-results/ https://insideevs.com/reviews/443791/ev-range-test-results/

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ed_balls 3y ago

> ~27% of the energy required to run a normal car It would be slightly worse in colder climates. I wish car manufactures would allow for easy installation for range extenders in the front trunk. I'd be a great source of heat for the heat pump. Range anxiety would be gone. No carbon tax since it would be an aftermarket solution. It seems Mazda MX-30 r-ev is the only thing you can buy.

kwhitefoot 3y ago
> Range anxiety would be gone. Range anxiety is an affliction more common among those who do not drive an EV than those who do.
- mdp2021 3y ago
  > is an affliction more common among That is a tautology... "Those who weigh the downside more remain in the alternative option." What did you want to mean?
  - vel0city 3y ago
    Their point was that a number of people who have range anxiety are those who haven't actually looked at what the impact of changing to an EV would actually be. Which, for a lot of people, wouldn't be nearly as much as they would think. A lot of people with range anxiety probably use an EV with little to no impact in their driving habits other than plugging in when they get home. But they're so concerned with "what if's" that rarely ever come up in their lives. "But what if I suddenly need to drive across the country taking only back country roads and avoiding all highways across the furthest north roads in the coldest of winter?? Can't do that in an EV!" The most common reactions I get to people asking about my EV are along the lines of "But how do you charge it? Don't you have to wait at public chargers all the time? It must be so challenging driving an EV with so many broken chargers all the time! You must have to wait so long all the time for all that charging, its so slow!" Which is quite strange, because the vast majority of charging sessions most EVs would probably experience are plugging in at their home entirely negating these concerns. For a lot of those people asking me those questions (often friends and family), I know they'd be able to replace a car with an EV and have only positive impacts other than the costs of buying a new car (something they do on some schedule regularly). But the talking heads on the TV tell them EVs == slow, unreliable, expensive charging so clearly all EV owners must be dealing with largely unavailable, unreliable, expensive, slow charging all the time. When in reality I spend more time pumping gas in my ICE than I do waiting on my EV to charge, I've encountered more broken gas pumps than charging dispensers in the last year, and it costs me almost 10x less in energy cost than my ICE per mile.

jillesvangurp 3y ago

Not only that. The more important conclusion is that actually ICE cars are stupendously inefficient. All that extra energy ICE cars carry isn't actually being put to use very well. They don't have more powerful engines. They don't have more torque. They don't have more acceleration. And even their range isn't that much better. You can of course get models that take something like 100+ liters of petrol. But the per liter performance only gets worse if you do that (heavier cars are less efficient). The reality is that yes, fuel is very energy dense but sadly most of that isn't transformed into motion when you use it. You are instead making lots of noise (vibrations) and heat. Both are actually bad for your car. So, you use most of the energy to wear out your car faster. The more powerful the car, the less efficient they are. And the faster they break down.

vivegi 3y ago

I have a fundamental question though. Will EVs (Li battery based) achieve the holy grail of IC engine replacement? Earth's Lithium deposits.................. 88,000,000,000 Kilograms [2], [3] @25% Viable for mining.................... 22,000,000,000 Kilograms [2], [3] Tesla S battery weight.................... 540 Kilograms per car [4] Lithium weight per Tesla S battery........ 63 Kilograms per battery [4] Max Tesla S (global) production possible.. 349,206,349 units (See Edit below) Number of automobiles running in the USA.. 102,000,000 units [1] Number of automobiles running in the World 1,500,000,000 units [5] So, even if we theoretically assume that the earth's entire known Li reserves are used for EV usage, we cannot replace more than 25% of the currently running cars in the world. So, we have a bigger problem ahead of us (over the next decade) that will act as an opposing force against EV penetration and replacement of the IC engine. Solutions possibly lie in exploring other battery chemistries while improving the efficiency of Li extraction. Edit: As some of the comments below point out, the Li content in a Tesla Model S battery is approx. 63 Kg. That makes the Max Tesla S (production) possible to 349 million units. So, in theory, one could replace all IC engines in automobiles plying in the USA. That then leaves the rest of the world. So, the problem still remains. [1]: https://www.fhwa.dot.gov/policyinformation/statistics/2021/mv1.cfm https://www.fhwa.dot.gov/policyinformation/statistics/2021/m... [2]: https://www.popularmechanics.com/science/energy/a42417327/lithium-supply-batteries-electric-vehicles/ https://www.popularmechanics.com/science/energy/a42417327/li... [3]: https://www.usgs.gov/centers/national-minerals-information-center/lithium-statistics-and-information https://www.usgs.gov/centers/national-minerals-information-c... [4]: https://blog.evbox.com/ev-battery-weight https://blog.evbox.com/ev-battery-weight [5]: https://www.weforum.org/agenda/2016/04/the-number-of-cars-worldwide-is-set-to-double-by-2040 https://www.weforum.org/agenda/2016/04/the-number-of-cars-wo...

tryptophan 3y ago
Known Earth's Lithium deposits =/= Earth's Lithium Deposits
- epistasis 3y ago
  And in fact this number changed by large amounts in the last decade, even before the current boom of the 2020s. Remember peak oil, which was a big panic of some in the 2000s? It turns out that peak production didn't happen overall, but if you look at the original set of "known resources", the peak oil predictions were spot on. Yet we didn't experience huge oil supply shortages because huge expenditures into new fracking tech enables far more resources to be accessed. We have always loved in a complete abundance of lithium, so we never bothered to look for more resources. Now that we need more, we will find it. It's not a particularly rare element.

codethief 3y ago

> 31mpg mpg = miles per gallon

steveBK123 3y ago

Relative efficiencies also explain why city/highway efficiency is inverted between EV & ICE. Gasoline is rather energy dense, but the ICE is rather wasteful. There is a certain base load of energy being generated by an ICE engine, regardless of if you are moving or how slow you go. This is why carmakers experimented with things like rapid stop/start engines, regen batteries&motors, etc. ICE becomes more efficient as you reach highway speeds, which is why highway mpg is better than city mpg. Batteries by contrast are not very energy dense, while EV motors are extremely efficient. The only energy being consumed is that which is needed to move the car, plus fight rolling & wind resistance, and power AC/heat. Wind resistance increases with the square of speed. EVs as a result are most efficient at low speed, and at highway speeds become noticeably less efficient as you go from 55->65->75mph. This is also why running AC/heat has a noticeable impact on range in EVs.

dahfizz 3y ago
Meh, the only reason EVs are more efficient in the city is because of regen braking. An ICE car traveling at a constant 30mph is going to get much better fuel economy than an ICE car traveling at a constant 75mph. The difference is that <=30mph roads usually have a lot of stop-and-go.
- steveBK123 3y ago
  ICE efficiency also more driven by RPM & therefore where you are in the gears. So ICE designers have decisions to make about which speeds to optimize for. ICE peak efficiency tends to be more around 45mph than 30mph. But yes, the less you brake in an ICE, the more efficient. Hybrids give you a bit of the ICE range/highway efficiency with the EV city driving efficiency, with the added complexity of having ICE & EV under one hood.
  - rootusrootus 3y ago
    A modern 8-10 speed automatic transmission can easily put the engine at or near the ideal consumption RPM whether it's 30 mph or 80 mph. If we really cared about efficiency, we'd have smaller motors. Throttling decreases efficiency, so the best mileage is going to be cruising at WOT (naively assuming no fuel mixture enrichment, which isn't always true). A classic example of this strategy is an old Geo Metro. Light, tiny motor, and barely capable of maintaining highway speed using peak horsepower.

jvanderbot 3y ago

in practice, I get 400Wh/mi. So, 50%?

osigurdson 3y ago

This is definitely not an apples-to-apples comparison. With an EV the ball is already at the top of the hill and merely needs to be rolled down, with an ICE car, the ball has to be pushed up the hill first. The power plant does all of the heavy lifting for the EV. Not a mark against EVs of course - it kind of just makes sense. I'm sure future generations will laugh that every vehicle used to have its own on-board power generation facility. It's too bad the dumb power-plant-under-hood way is still so much cheaper than the EV approach of course.

dd36 3y ago
It’s not cheaper.
- osigurdson 3y ago
  If EVs were cheaper, everyone would own one.
  - dd36 3y ago
    Only those buying news cars would own one. And that is beginning to happen.

Keyframe 3y ago

For a normal, new car, anything above 6l/100km for that size of a car (and usually around 5) is something's wrong with the car. That's more than twice the efficiency of described one from 1976.

thebigspacefuck 3y ago

Isn’t this what the MPGe rating tells you?

strangescript 3y ago

Its almost like electric cars are cleaner, more efficient and better for the environment. Telsa's are god tier level of engineering under the hood. (Maybe not so much fit and finish). The only reason the gov't isn't buying these for everyone is because Tesla disrupted deeply entrenched companies and people don't like Elon.

timbit42 3y ago

The Aptera gets 1000 miles on a 100 kWh battery. Porsche Taycan: 2 miles per kWh Tesla Model 3: 5 miles per kWh Lightyear Zero: 7 miles per kWh Aptera: 10 miles per kWh Source: https://www.youtube.com/watch?v=mpiH-Y-HOvE https://www.youtube.com/watch?v=mpiH-Y-HOvE

vel0city 3y ago
> The Aptera gets 1000 miles on a 100 kWh battery. The Aptera gets 0 miles on a 0 kWh battery because they've shipped 0 cars, right? Can I go buy one and drive it today?
- timbit42 3y ago
  What makes you think it won't get to market? Sure, they failed in the past but they have the money now and they've certainly shown they won't give up.
  - vel0city 3y ago
    > The Aptera gets 1000 miles on a 100 kWh battery. Gets, as in present tense. A theoretical car made sometime in the future shouldn't use present tense terminology. No consumer on the road today is getting 1,000mi on a 100kWh battery in an Aptera. If Aptera manages to actually ship cars, then the word "gets" is accurate. > What makes you think it won't get to market? See: > Sure, they failed in the past Building cars has extremely high barriers to entry. Getting things approved costs tons of money. Spinning up factories is no small challenge. Actually making more than one or two cars is incredibly challenging. Meanwhile, in order to spread those costs out you'll hopefully want to make a lot of them otherwise a good chunk of your value proposition goes away as the costs for the car would quickly get out of hand. Then comes the challenges of actually selling them at any volume. I legally can't buy one in my state if they don't create a franchise dealer network. Its hard to get shoppers to compare your vehicles if you don't have a way for them to actually buy the cars. Tesla manages because they spent a ton on "galleries", they were the only real EV option for a while, and have massive brand presence. Ask any random average car buyer if they've thought of buying an Tesla, and they'll probably have an opinion. Ask anyone if they've thought of buying an Aptera, and they'll probably have no clue what you're talking about. If Aptera manages to actually make some cars, that's great! Even better if they manage to sell them for profit. Its good to have more competition. But I'm not holding my breath.

alliao 3y ago

model Y consistently do 150Wh/km which is just nuts... one thing with petrol chemical too is it's not carrying all the energy with it, the oxygen came from atmosphere while EV is carrying the entire energy required to run with itself..