lukestern:

Bigger wheels absolutely KILL range and this apply for all EVs. The Audi tested by Top Gear had 20" and the Model X had 22". I would say that the wheels alone on the X account for about 15-20% higher consumption vs 20". The E-tron can also be optioned with 21" and 22" so a more fair comparison would be to run the test with the same wheel and tire size. Not saying that the TopGear test was bad, because it wasn't and I did find it quite balanced. But if discussing pure range and efficiency and draw any conclusions it was not a good test due to the difference in wheel size highlighted.

With the newer more efficient motors Tesla now have in production for X/S I'd give a qualified guess that the Model X will have about 25-30% less consumption on average if both the E-tron and X run on 20" tires and under the same driving conditions. Increase the average speed and the E-tron will fall behind even further due to worse aero (Cd and CdA).

I'm probably one of few in here (maybe the only one?) who have driven all these cars quite extensively (E-tron, I-Pace and all the Teslas) probably a lot more than any of the TopGear testers and I of course have my own opinion about each of the cars. But when it comes to efficiency and range in the real world, the Teslas win hands down I can say with confidence based on my own tests and findings.

 

Now you are really pushing it. 

Different manufacturers spec different diameters for aesthetic purposes. Within Model X, going from 20" to 22" does't change the overall diameter of the wheel/tire combo, more wheel less tire only. The gearing stays the same. Larger wheels weights more but in the grand scheme of things it's minuscule as the weight of the tire also decreases at the same time. 

Wheels designs however makes much more of a difference, hence why most EV cars comes with ugly aero oriented wheels. Normal cars, especially performance cars, have wheel designs that extract hot air out for cooling purposes, the down side to drag is secondary. EV cars comes with aero wheels that makes drag reduction top priority and pushing the cooling part as secondary, normally it doesn't matter anyway as EV cars have regen braking. 

 


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