Interesting point. Wondering how the EPA got it so wrong, and why the numbers aren't skewed consistently across all the car makers? Not implying anything, I'm just thinking it through.
Well, we don’t really know that they did. They certainly don’t drive the car at 70+ mph for hours and figure out how far it will go… nor do they drive it in 104 heat in AZ, around town and on the highway to test range. They have a test Loop they use, which mimics urban and highway driving. Acceleration needs, HVAC, etc. Then, some of that range measurement is reduced due to a multiplier, like .6 or .7, to indicate essentially “real world mileage expectation”.
MAYBE Tesla has figured out how to game the system, essentially knowing the test parameters, and ultimate outcome so they setup the car - and not just test mules - to be able to make most use of the test. I’ll call this the Kobayashi Maru effort. ;-)
My 2018 M3 LR will go 550-600 miles, IF I drive it on a flat surface at 32 miles an hour, not using the heater or the HVAC. That just isn’t realistic of course, but I know that I can get to 120 watts per mile if I REALLY need to. Nobody wants that though.
Overall, driving around town, driving on highways - usually faster than 95% of other cars, 73 in 65, 83 in 70, etc. I average ~ 93% efficiency, which means I can expect ~ 285 miles on a car rated at 310. At highway speeds, agains 77-80, cool temps, no heat, no elevation changes I’m doing ~ 265 watt/mile. That puts my expected range at about 300 miles. My average summer season wh/mile is 220, my overall LIFETIME average is 235 wh/mile.
As others have indicated, speed ‘kills’ efficiency. Not as much as some have indicated though. While the difference in efficiency between 55-60 average speed and 70 overall is measurable, it’s not as “dramatic” as one might think. It’s not 25% less efficient, or 50% less efficient - all things remaining equal. It’s probably closer to 12-15% less efficient, maybe 20% at the outside.
I am certain that if I charged my car to 100%, drove 60-65 mph on a highway in late May, just drove a circular test loop so reducing lots of elevation changes, i could get at least 290-300 miles on a full charge. I just don’t have 5-6 hours to test it out.
I will say, that one thing that is VERY different in EV cars vs. the majority of ICE cars is instant torque. And it’s quite addictive. From stop to launch, even in lower performance models, the cars get their HIGHER overall mass up to speed much faster than average ICE cars. Same with passing, accelerating from an on ramp. Passing cars on a highway, etc. EVERY time one does that, which the cars do VERY well is a significant energy drain and essentially the LEAST efficiency one can have. It’s why cars have “chill” mode, because it nerfs that ability a bit and makes people drive or at least accelerate more conservatively overall - at least from an acceleration standpoint. I have the feeling that a lot of ppl with new EV and that are NEW to EV really enjoy all that POWER and use it often - I mean WHY NOT… but at the cost of reducing overall efficiency quite a bit.
here’s a little bit about how the EPA tests range