I'm currently in the final stages of pulling the trigger on a Tesla Model Y LR and have been getting into the weeds researching things, as this will be my first electric vehicle (currently driving around a gas sucking F150 EcoBoost), and have a few thoughts to share.
I feel like a part of the temperature effect on range is related in a pretty significant way to not just climate control/battery heating, but also to density altitude. Colder air can be quite a bit more dense than hot air, which would likely have pretty a pronounced impact on efficiency, especially at higher speed. Without nerding out too much on air density (I work in the aviation field, where we're constantly concerned with how environmental conditions will affect aircraft performance), comparing two days here in Las Vegas (January 3, 2023 vs July 31, 2023) shows pretty remarkable differences in density. (
Weather Underground History -
NWS Density Altitude Calculator)
January 3 DA (42° f , 27.84", 36.5°DP) = 1434.5ft DA
July 31 DA - (105° f, 27.68", 45.5°) = 5611ft DA
With Vegas being at just over 2,000ft, I suspect you'd see remarkable higher air density in areas with lower elevation and colder winter temperatures. Any car is going to deal with increased friction as it passes through the air at higher speeds, however an ICE car will actually be capable of creating quite a bit more power in low density altitudes vs high density altitudes. More power would, in theory, equate to reduced fuel consumption to accelerate at a set speed. If you're skeptical, take a look around at some drag race time comparisons between a place like San Diego and somewhere in Colorado. I recall reading a study awhile back comparing a BMW M3 to a Prius on a track, where the Prius needed to maintain 60mph and the M3 just had to pace it - the M3 actually returned higher fuel economy numbers, as the reduced power really required the car to use nearly
all of it's available power to maintain speed. While the fuel economy differences may not be as pronounced in an ICE vehicle, taking a totally unscientific look through
Fuelly and picking a car at random will generally show you decreased fuel economy numbers during the winter (Jan/Feb vs June/July) (probably somewhere in the neighborhood of -10%). This is probably a combination of climate, idle time spent warming up, and increased air density.
A BEV will deal with the same decrease in aerodynamic efficiency, but will also gain no additional power through more efficient combustion. Traveling at 70mph vs 55mph is probably generating almost twice the drag (I looked around but can't find the exact cross-sectional area for a MY to calculate). Combine that with the already increased air density, and you're going to have a dramatic increase in the amount of energy needed to move. I actually found an article where a pair of drivers took a Tesla around 600 miles on a single charge, all by limiting speeds to around 25mph. I think this really speaks to the effect that speed has on range, and think that this effect is probably more pronounced in a BEV vs in an ICE vehicle because of the differences in amount of energy on the vehicles.
With increased energy usage through climate controls, and I feel like it's not going to be uncommon at all to see reduced efficiency in the range of 20-30% when the only factor is speed. Add in the multiple hits that temperature brings, and I suppose the 30-50% reduction in range makes a good bit of sense.
