I did a similar test in March in the VW ID4 (which I mentioned in this thread). 70mph got me 2.9mi/kwh whereas 80mph got me 2.5mi/kwh. My test wasn’t as thorough as theirs but it’s around the 12-15% mark in range loss. City driving gets me 3.6mi/kwh.
This was in March so will be a bit higher in summer and quite a bit lower in winter.
That’s not really unique to EVs. At speed, aerodynamic drag is the largest force working against you, and drag is proportional to the square of speed. 80mph is 14% faster than 70mph, so 31% more drag. Now, friction in the engine/motor and the gears, and between the tires and the road, those are proportional to speed, so those will factor in a bit, but I’d say what they observed is close to expected.
Years ago, I put a roof rack on my BMW, I kept track of my mpg pretty well and it cost me something like 1.5mpg on the highway when it was just the bars on top, no cargo. Aero is huge at highway speeds.
I’ve done a few trips in my Tesla, a 150-ish mile stretch from me to the nearest charger south of me. If I stick to the posted speed limit I can get there with a 48-50% charge. If I go 5mpg over it’s more like 42-44% SOC upon arrival.
I think the speed limit also helped make the roads safer. Along with improvements in vehicle design this led to a dramatic drop in deadly car accidents.
Model 3 is right at two tons in AWD trim and 3,600lb with RWD - the RWD gets a smaller battery as well, 50kWh. Mini says 65kWh for theirs, so ballpark I’d guess 3,800lb or so?
I just had a dealer tell me that she will not sell me a hybrid vehicle that I am interested in because I do not live in the state where the vehicle and dealership are.
They have the right to sell to whomever they want. It could be due to how commissions and fees and backdoor deals are made by dealerships. This also happens to Canadians who want to buy cars in the states to save on taxes and price gouging by the Canadian dealerships.