4 ms·

Having road tripped from Florida to Washington and back in a big circle around the country, it is my firm belief that every single person complaining about the

by elif 2y ago

Having road tripped from Florida to Washington and back in a big circle around the country, it is my firm belief that every single person complaining about the range estimates in a Tesla is speeding. By altering my driving style, I can get more range than the estimate. It's extremely predictable and accurate, to the point where I can notice the power drain from the self driving computers/cameras, arrive at the next supercharger at exactly the 3% I aim for, etc. There was a point in my road trip when I was on top of a mountain, and it said I would reach the next charger 100km away with 20km of range remaining, but I was only at 90km at the time. I made it with 17km of range remaining. The estimates are really good and useful if you don't speed.

ejoso 2y ago
Makes me wonder how it is stated. Normal driving conditions for many (most?) drivers is faster than the posted speed limit.
mvdtnz 2y ago
[flagged]
decimalenough 2y ago
The article is talking not about the route planner, which I agree usually gives very accurate estimates for specific routes, but the advertised theoretical driving "EPA ranges", which are quite inflated. However, from what I can tell, the EPA numbers from all manufacturers are quite unrealistic, because the methodology doesn't match real-world driving.
- dbcurtis 2y ago
  Yes, this is certainly true for ICE vehicles. The measurement methodology is spelled out in exacting detail, and yields highly repeatable results. Realistic? Nope, not at all. Nobody could claim that. But, it is repeatable and comparable, so that you can compare car A to car B. It gives you a strict rank order for vehicles that are driven exactly the same way, it just so happens that no person drives exactly that particular way. The utility is in providing a repeatable point of comparison. Is that useful?... forgive me for saying it, but YMMV.
- smallmancontrov 2y ago
  The problem with EPA range is that it's a compromise between highway range and city range, so it's almost guaranteed to poorly match your driving unless your daily driving mix equals the averages. This is a consequence of insisting on one number, not inflation. Inb4 "just pick highway range and be conservative" -- no, because then you will buy a car with great aerodynamics and terrible regen and spend all day driving it around the city using the terrible regen and not using the great aerodynamics.
  - prmoustache 2y ago
    EPA is a comparison tool, not a range estimation for everyone's regular drives.
dyauspitr 2y ago
Speeding is a given, even a necessity on most US highways. Everyone is speeding by 10 maybe even 15 mph as a baseline.
- prmoustache 2y ago
  I don't think it is a necessity. People just don't generally have patience. Generally people driving classic/collectible cars usually run at or below speed limits and...they are fine. You just have to embrace being overtaken by everyone. It is especially hard for people suffering with fragile masculinity though.
  - elif 2y ago
    Agree completely. People think they are being safer by going fast "with the flow" while in reality statistics refute this perspective entirely. Slower is safer periodt.
cwillu 2y ago
I have an old toyota camry hybrid. The estimated range is calculated based on the trip mpg, and as such is accurate when I'm going like a speed demon or cruising along at 90kph. Displaying a marketing number on the dash is inexcusable, regardless of how fast or slow drivers are going.
SkyPuncher 2y ago
When you understand how the EPA actually test this, it makes sense. "Highway" isn't anything like what most people think it is. It's not cruising at 75mph with no traffic on a major interstate. It's more like busy country road driving. > The "highway" program, on the other hand, is created to emulate rural and interstate freeway driving with a warmed-up engine, making no stops (both of which ensure maximum fuel economy). The vehicle is driven for 10 miles over a period of 12.5 minutes with an average speed of 48 mph and a top speed of 60 mph Further, the force of drag grows exponentially with speed. Going 75mph on the interstate is massively less fuel efficient than 48mph. https://auto.howstuffworks.com/fuel-efficiency/fuel-economy/28004-epa-fuel-economy-explained.htm https://auto.howstuffworks.com/fuel-efficiency/fuel-economy/...
- tromp 2y ago
  > force of drag grows exponentially with speed No, it grows only polynomially [1]. [1] https://en.wikipedia.org/wiki/Drag_equation https://en.wikipedia.org/wiki/Drag_equation
  - fransje26 2y ago
    More specifically, it grows quadratically.
  - SkyPuncher 2y ago
    You're right. Though, it doesn't really take away from my underlying point.
- Gasp0de 2y ago
  As a German, I love how you call 75mph speeding. There is a huge discussion going on in Germany of introducing a 80mph speed limit on the highway and many people claim that that does not work for them as they regularly drive 100mph average.
  - fransje26 2y ago
    > they regularly drive 100mph average You don't drive 100mph average on German motorways. Especially with the trucks not giving a damn and forcing themselves through to the left lane to pass their colleagues driving 2 kph slower, arriving traffic be damned.
some1else 2y ago
> There was a point in my road trip when I was on top of a mountain, and it said I would reach the next charger 100km away with 20km of range remaining, but I was only at 90km at the time. I made it with 17km of range remaining. This is how regenerative braking works
- elif 2y ago
  Correct, my point is the software prediction knew almost exactly how much energy would be recovered by it. Supporting my thesis that it is a very accurate system.
jillesvangurp 2y ago
It's a valid point. The drag doesn't go up linearly as you accelerate but exponentially. So driving 5, 10, or 20 miles per hour faster at highway speeds has a huge impact. Your speed goes up by a few percent but the drag goes up a lot more. Also nice to keep in mind if you are driving a petrol car. Because the difference comes out of your pocket and the physics works the same way. The estimate the car gives you adjusts to what you are actually doing. So if you drive uphill very quickly (which is tempting because of all that wonderful torque you have), that number will get very low quickly. If you drive a really heavy car, physics dictates that you will use up a lot of kwh. The estimate will recover a bit if you level off for the remaining kwh. And you might even get a few kwh back if you go downhill via regenerative braking. But not all of it. It's probably merely reducing the number of kwh you lose rather than adding a lot back. A more useful metric than range is miles per kwh at different speeds or under different conditions. The amount of kwh your battery has is a constant; but miles you get per kwh will vary depending on what you are doing. Teslas are normally around 3.5-4 miles per kwh on highways, which is pretty good for cars that size. But of course it matters how fast you are going. That puts them around the 200-250 miles range many people are reportedly getting; if you account for battery degradation, temperature, etc. and assume a 65kwh battery. Some recent cars are getting a lot of gains from improved aerodynamics and battery management. E.g. Kia is doing some great stuff on that front. Also having less battery actually improves the miles per kwh number because there's less mass to drag around. Shoving 200kwh in a big truck makes it really heavy and combined with poor aerodynamics probably would make for less than stellar range than you might hope for. Probably you're getting less than 2 miles per kwh. So, more than triple the battery but nowhere near triple the range. And it makes the truck really expensive too. And you'll have to buy a lot more kwh to go the same distance.
- rmu09 2y ago
  Energy needed for elecation gain when going uphill is independent of speed (to first order, losses in drivetrain are probably a bit higher when driving with higher power). Available max and continuous torque of electric vehicles isn't necessarily that high compared to ICE vehicles, whats really different is that torque is available instantly and from near 0 RPM and the motor reacts more or less "instantly". BTW, combining "miles" and "kWh" is strange, shouldn't that be pound*mile²/h ?

by elif 2y ago

ejoso 2y ago

Makes me wonder how it is stated. Normal driving conditions for many (most?) drivers is faster than the posted speed limit.

mvdtnz 2y ago

[flagged]

decimalenough 2y ago

The article is talking not about the route planner, which I agree usually gives very accurate estimates for specific routes, but the advertised theoretical driving "EPA ranges", which are quite inflated. However, from what I can tell, the EPA numbers from all manufacturers are quite unrealistic, because the methodology doesn't match real-world driving.

dbcurtis 2y ago
Yes, this is certainly true for ICE vehicles. The measurement methodology is spelled out in exacting detail, and yields highly repeatable results. Realistic? Nope, not at all. Nobody could claim that. But, it is repeatable and comparable, so that you can compare car A to car B. It gives you a strict rank order for vehicles that are driven exactly the same way, it just so happens that no person drives exactly that particular way. The utility is in providing a repeatable point of comparison. Is that useful?... forgive me for saying it, but YMMV.
smallmancontrov 2y ago
The problem with EPA range is that it's a compromise between highway range and city range, so it's almost guaranteed to poorly match your driving unless your daily driving mix equals the averages. This is a consequence of insisting on one number, not inflation. Inb4 "just pick highway range and be conservative" -- no, because then you will buy a car with great aerodynamics and terrible regen and spend all day driving it around the city using the terrible regen and not using the great aerodynamics.
- prmoustache 2y ago
  EPA is a comparison tool, not a range estimation for everyone's regular drives.

dyauspitr 2y ago

Speeding is a given, even a necessity on most US highways. Everyone is speeding by 10 maybe even 15 mph as a baseline.

prmoustache 2y ago
I don't think it is a necessity. People just don't generally have patience. Generally people driving classic/collectible cars usually run at or below speed limits and...they are fine. You just have to embrace being overtaken by everyone. It is especially hard for people suffering with fragile masculinity though.
- elif 2y ago
  Agree completely. People think they are being safer by going fast "with the flow" while in reality statistics refute this perspective entirely. Slower is safer periodt.

cwillu 2y ago

I have an old toyota camry hybrid. The estimated range is calculated based on the trip mpg, and as such is accurate when I'm going like a speed demon or cruising along at 90kph. Displaying a marketing number on the dash is inexcusable, regardless of how fast or slow drivers are going.

SkyPuncher 2y ago

When you understand how the EPA actually test this, it makes sense. "Highway" isn't anything like what most people think it is. It's not cruising at 75mph with no traffic on a major interstate. It's more like busy country road driving. > The "highway" program, on the other hand, is created to emulate rural and interstate freeway driving with a warmed-up engine, making no stops (both of which ensure maximum fuel economy). The vehicle is driven for 10 miles over a period of 12.5 minutes with an average speed of 48 mph and a top speed of 60 mph Further, the force of drag grows exponentially with speed. Going 75mph on the interstate is massively less fuel efficient than 48mph. https://auto.howstuffworks.com/fuel-efficiency/fuel-economy/28004-epa-fuel-economy-explained.htm https://auto.howstuffworks.com/fuel-efficiency/fuel-economy/...

tromp 2y ago
> force of drag grows exponentially with speed No, it grows only polynomially [1]. [1] https://en.wikipedia.org/wiki/Drag_equation https://en.wikipedia.org/wiki/Drag_equation
- fransje26 2y ago
  More specifically, it grows quadratically.
- SkyPuncher 2y ago
  You're right. Though, it doesn't really take away from my underlying point.
Gasp0de 2y ago
As a German, I love how you call 75mph speeding. There is a huge discussion going on in Germany of introducing a 80mph speed limit on the highway and many people claim that that does not work for them as they regularly drive 100mph average.
- fransje26 2y ago
  > they regularly drive 100mph average You don't drive 100mph average on German motorways. Especially with the trucks not giving a damn and forcing themselves through to the left lane to pass their colleagues driving 2 kph slower, arriving traffic be damned.

some1else 2y ago

> There was a point in my road trip when I was on top of a mountain, and it said I would reach the next charger 100km away with 20km of range remaining, but I was only at 90km at the time. I made it with 17km of range remaining. This is how regenerative braking works

elif 2y ago
Correct, my point is the software prediction knew almost exactly how much energy would be recovered by it. Supporting my thesis that it is a very accurate system.

jillesvangurp 2y ago

It's a valid point. The drag doesn't go up linearly as you accelerate but exponentially. So driving 5, 10, or 20 miles per hour faster at highway speeds has a huge impact. Your speed goes up by a few percent but the drag goes up a lot more. Also nice to keep in mind if you are driving a petrol car. Because the difference comes out of your pocket and the physics works the same way. The estimate the car gives you adjusts to what you are actually doing. So if you drive uphill very quickly (which is tempting because of all that wonderful torque you have), that number will get very low quickly. If you drive a really heavy car, physics dictates that you will use up a lot of kwh. The estimate will recover a bit if you level off for the remaining kwh. And you might even get a few kwh back if you go downhill via regenerative braking. But not all of it. It's probably merely reducing the number of kwh you lose rather than adding a lot back. A more useful metric than range is miles per kwh at different speeds or under different conditions. The amount of kwh your battery has is a constant; but miles you get per kwh will vary depending on what you are doing. Teslas are normally around 3.5-4 miles per kwh on highways, which is pretty good for cars that size. But of course it matters how fast you are going. That puts them around the 200-250 miles range many people are reportedly getting; if you account for battery degradation, temperature, etc. and assume a 65kwh battery. Some recent cars are getting a lot of gains from improved aerodynamics and battery management. E.g. Kia is doing some great stuff on that front. Also having less battery actually improves the miles per kwh number because there's less mass to drag around. Shoving 200kwh in a big truck makes it really heavy and combined with poor aerodynamics probably would make for less than stellar range than you might hope for. Probably you're getting less than 2 miles per kwh. So, more than triple the battery but nowhere near triple the range. And it makes the truck really expensive too. And you'll have to buy a lot more kwh to go the same distance.

rmu09 2y ago
Energy needed for elecation gain when going uphill is independent of speed (to first order, losses in drivetrain are probably a bit higher when driving with higher power). Available max and continuous torque of electric vehicles isn't necessarily that high compared to ICE vehicles, whats really different is that torque is available instantly and from near 0 RPM and the motor reacts more or less "instantly". BTW, combining "miles" and "kWh" is strange, shouldn't that be pound*mile²/h ?