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I just finished 2k+ california => florida road trip in an electric car and can say with confidence that this comparison is total and utter garbage. Here are th

by kjksf 5y ago

I just finished 2k+ california => florida road trip in an electric car and can say with confidence that this comparison is total and utter garbage. Here are the factors that influence your total charge time. 1. Charger speeds vary from 50 kWh to 250 kWh. That's 5x difference just based on what charger you'll happen to use. 2. The energy usage (due to air resistance) is non-linear with speed. Driving at 85 mph could use twice as much energy as driving at 65 mph. How fast you drive will have an enormous effect on how much energy you use and therefore how much you'll need to recharge during the trip. In extreme case, you can hypermile i.e. drive very slowly. For example someone in 2018 Model 3 did 606 miles on a single charge (a car rated at less than 300 miles). It just took them 32 hrs because they drove so slowly (https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hypermilling-driving-record https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hy...) BTW: this is why EPA range is not representative. Their test is at 65 mph while my un-scientific observation of highway driving tells me people drive at least 75 mph. 3. Details of recharging matter because it's non-linear. Charging to 80% of battery takes roughly the same amount of time as charging remaining 20% to 100% 3. More people in car => more weight => more energy usage. Use a/c? More energy usage. Strong winds? More energy usage. Driving uphill? More energy usage. The point is that unless you strictly control for all those factors, any comparison is useless garbage, just like this click bait article with zero information about how the test was done. Those days you can't even trust car magazines to do a decent comparison test. If you want fair and scientific comparisons between various electric cars, Bjorn Nyland is your guy https://www.youtube.com/user/bjornnyland/videos https://www.youtube.com/user/bjornnyland/videos

thinkmassive 5y ago
Nit: kWh measures energy (battery capacity), and kW measures power (charger output ) Tesla Superchargers are 250 kW. Tesla Destination Chargers (and probably the majority of other EV chargers) are 50 kW.
lrem 5y ago
> BTW: this is why EPA range is not representative. Their test is at 65 mph while my un-scientific observation of highway driving tells me people drive at least 75 mph. Wait, is this really the speed of long-distance driving in the US? I've just did the conversion and when I'm taking kids to see their grandma, we set the cruise control to 110mph for the most part.
- ncmncm 5y ago
  I think you must have got a bit confused. What km/hr do you think you just quoted?
  - lrem 5y ago
    180km/h Edit: this doesn't make it my average speed, as much of the time is spent decelerating because of whatever is happening and accelerating back. The average through that 850km stretch is likely closer to 160km/h, I should measure it one day. For the curious: over the whole 3000km roundtrip I seem to be burning fuel at about 7l/100km, or 33.6mpg.
    - ncmncm 5y ago
      OK, I concede you were serious. Is this on the Autobahn?
      - lrem 5y ago
        Yup, the only place where you can go over 140.
        seanmcdirmid 5y ago
        Montana didn't have speed limits until 1999.
        AnimalMuppet 5y ago
        Not sure that's quite true. They had "reasonable and prudent", IIRC, which meant that a cop could still write you a ticket for 140. If there was much other traffic around, he might have been justified in doing it.
        seanmcdirmid 5y ago
        > They had "reasonable and prudent", IIRC Isn't that the same guidance as the Autobahn? Also, I get it for eastern MT, but my mom and step dad were living in Helena at the time, and my step dad drove way too fast for those unstraight mountain roads. It wasn't just traffic that they brought the speed limits back for.
pornel 5y ago
The points you're making are valid, but the article is about a Guinness World Record. A world record is by definition the best case, and it must have been verified by Guinness. I don't think anyone expects their Sunday road trip to beat a world record.
- jhgb 5y ago
  World record in exactly what, however? Not in total trip time since the old record is way better than the new one in this respect (like, one third time of the new one). I'm pretty sure that if someone attempted that in a Tesla, it would be much better than at triple the speed. Apples and oranges here.
  - boibombeiro 5y ago
    in time spent charging. it is in the article
    - jhgb 5y ago
      In that case that's not even what the old ride was trying to minimize, which was apparently total trip time (driving+charging). Apples and oranges here.
anchpop 5y ago
> The energy usage (due to air resistance) is non-linear with speed. Driving at 85 mph could use twice as much energy as driving at 65 mph. Does this mean I'll use twice as much gas when driving an ICE car at 85 vs 65? Or do gas cars have a higher constant factor or something that makes air resistance relatively less important?
- Tade0 5y ago
  > Does this mean I'll use twice as much gas when driving an ICE car at 85 vs 65? Probably closer to 50% more, because while drag is roughly proportional to the square of speed (which would yield ~70% more with this speed difference), there is also rolling resistance and powertrain losses - so the function of energy consumption vs speed is of the form: ax^2 + bx + c("c" being accessories like air conditioning).
- mayama 5y ago
  Gas cars lose energy to heat loss and timing/efficiency of combustion cycle, that due to air drag. So even though you could gain little more mileage driving at 65mph, the relative difference is less compared to electric cars.
- mint2 5y ago
  Others answered about engines efficiencies. air resistance doesn’t care whether the motive force is a gas engine, electric motors, nuclear powering steam turbines, Flinstone feet, or a wound up spring. All that matters is the cars form factor, i.e. the shape and texture of the outer shell.
MisterTea 5y ago
> In extreme case, you can hypermile i.e. drive very slowly. For example someone in 2018 Model 3 did 606 miles on a single charge (a car rated at less than 300 miles). It just took them 32 hrs because they drove so slowly (https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hy https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hy...) It was done on a closed loop track 1 mile long driving 20-30mph.
geoduck14 5y ago
Serious question: How was the drive? I'm in Texas and I like to drive to Orlando. Did you have to change your driving style much from do it in an EV?
- kjksf 5y ago
  It took me 5 days to go from San Diego to Miami. Could have done in 4 but first 2 days I stopped driving early (6 pm instead of 8-9 pm). Maybe even 3 if really pushed it. I did it in Model 3 LR which is rated ~335 miles but I was driving fast (75-90 mph) and my car was loaded with boxes so I got ~220 miles between stops. I did 3 or 4 stops a day, 30 min - 1hr per stop, which I used to eat and rest. About 2-3 hrs of driving between stops. The car told me where and when to stop. I just typed the destination address and followed what Tesla navigation system told me. One time it even warned me to slow down so that I don't run out of battery (I was driving 85 mph and slowed down to 75 mph). First day I used autopilot but I didn't like how often it kicked me out thinking I'm not paying attention. Rest of the time I used adaptive cruise control which was amazing. I could just focus on the steering (and there wasn't much of it on those straight highways). In summary, driving for 5 days straight sucks no matter what car. Tesla's built-in navigation and adaptive cruise control made the trip so much better. Built-in spotify was also great (listened to some music and some podcasts).

by kjksf 5y ago

thinkmassive 5y ago

Nit: kWh measures energy (battery capacity), and kW measures power (charger output ) Tesla Superchargers are 250 kW. Tesla Destination Chargers (and probably the majority of other EV chargers) are 50 kW.

lrem 5y ago

> BTW: this is why EPA range is not representative. Their test is at 65 mph while my un-scientific observation of highway driving tells me people drive at least 75 mph. Wait, is this really the speed of long-distance driving in the US? I've just did the conversion and when I'm taking kids to see their grandma, we set the cruise control to 110mph for the most part.

ncmncm 5y ago
I think you must have got a bit confused. What km/hr do you think you just quoted?
- lrem 5y ago
  180km/h Edit: this doesn't make it my average speed, as much of the time is spent decelerating because of whatever is happening and accelerating back. The average through that 850km stretch is likely closer to 160km/h, I should measure it one day. For the curious: over the whole 3000km roundtrip I seem to be burning fuel at about 7l/100km, or 33.6mpg.
  - ncmncm 5y ago
    OK, I concede you were serious. Is this on the Autobahn?
    - lrem 5y ago
      Yup, the only place where you can go over 140.
      - seanmcdirmid 5y ago
        Montana didn't have speed limits until 1999.
        AnimalMuppet 5y ago
        Not sure that's quite true. They had "reasonable and prudent", IIRC, which meant that a cop could still write you a ticket for 140. If there was much other traffic around, he might have been justified in doing it.
        seanmcdirmid 5y ago
        > They had "reasonable and prudent", IIRC Isn't that the same guidance as the Autobahn? Also, I get it for eastern MT, but my mom and step dad were living in Helena at the time, and my step dad drove way too fast for those unstraight mountain roads. It wasn't just traffic that they brought the speed limits back for.

pornel 5y ago

The points you're making are valid, but the article is about a Guinness World Record. A world record is by definition the best case, and it must have been verified by Guinness. I don't think anyone expects their Sunday road trip to beat a world record.

jhgb 5y ago
World record in exactly what, however? Not in total trip time since the old record is way better than the new one in this respect (like, one third time of the new one). I'm pretty sure that if someone attempted that in a Tesla, it would be much better than at triple the speed. Apples and oranges here.
- boibombeiro 5y ago
  in time spent charging. it is in the article
  - jhgb 5y ago
    In that case that's not even what the old ride was trying to minimize, which was apparently total trip time (driving+charging). Apples and oranges here.

anchpop 5y ago

> The energy usage (due to air resistance) is non-linear with speed. Driving at 85 mph could use twice as much energy as driving at 65 mph. Does this mean I'll use twice as much gas when driving an ICE car at 85 vs 65? Or do gas cars have a higher constant factor or something that makes air resistance relatively less important?

Tade0 5y ago
> Does this mean I'll use twice as much gas when driving an ICE car at 85 vs 65? Probably closer to 50% more, because while drag is roughly proportional to the square of speed (which would yield ~70% more with this speed difference), there is also rolling resistance and powertrain losses - so the function of energy consumption vs speed is of the form: ax^2 + bx + c("c" being accessories like air conditioning).
mayama 5y ago
Gas cars lose energy to heat loss and timing/efficiency of combustion cycle, that due to air drag. So even though you could gain little more mileage driving at 65mph, the relative difference is less compared to electric cars.
mint2 5y ago
Others answered about engines efficiencies. air resistance doesn’t care whether the motive force is a gas engine, electric motors, nuclear powering steam turbines, Flinstone feet, or a wound up spring. All that matters is the cars form factor, i.e. the shape and texture of the outer shell.

MisterTea 5y ago

> In extreme case, you can hypermile i.e. drive very slowly. For example someone in 2018 Model 3 did 606 miles on a single charge (a car rated at less than 300 miles). It just took them 32 hrs because they drove so slowly (https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hy https://www.theverge.com/2018/5/29/17405906/tesla-model-3-hy...) It was done on a closed loop track 1 mile long driving 20-30mph.

geoduck14 5y ago

Serious question: How was the drive? I'm in Texas and I like to drive to Orlando. Did you have to change your driving style much from do it in an EV?

kjksf 5y ago
It took me 5 days to go from San Diego to Miami. Could have done in 4 but first 2 days I stopped driving early (6 pm instead of 8-9 pm). Maybe even 3 if really pushed it. I did it in Model 3 LR which is rated ~335 miles but I was driving fast (75-90 mph) and my car was loaded with boxes so I got ~220 miles between stops. I did 3 or 4 stops a day, 30 min - 1hr per stop, which I used to eat and rest. About 2-3 hrs of driving between stops. The car told me where and when to stop. I just typed the destination address and followed what Tesla navigation system told me. One time it even warned me to slow down so that I don't run out of battery (I was driving 85 mph and slowed down to 75 mph). First day I used autopilot but I didn't like how often it kicked me out thinking I'm not paying attention. Rest of the time I used adaptive cruise control which was amazing. I could just focus on the steering (and there wasn't much of it on those straight highways). In summary, driving for 5 days straight sucks no matter what car. Tesla's built-in navigation and adaptive cruise control made the trip so much better. Built-in spotify was also great (listened to some music and some podcasts).