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After driving the cars on our biannual trips to Florida it appears I jumped the gun on assuming that the watt hour efficiencies of the 265/30 front tire were significantly less than the stock 235/35 Michelin Pilot Sport 4S tire in the front. We had a chance to do literally mile for mile at identical speed comparison of the two cars. My wife's car has the same degree of lowering with the MPP Comfort adjustable kit the same basic front air dam, and a stock Tesla 20in Pilot Sport in front and the Tesla spec 275/30 in the rear so it's not an efficiency champ by any means, but doing a mile by mile supercharger stop by supercharger stop comparison, the two cars were within 1 - 2 Watt hours per mile of each other. This means that the additional width of the 265/30 Pilot Sport 4S tire is essentially a wash in efficiency. Seems like a good way to get some extra grip without penalty. There is a slight loss of rolling diameter about 1% but it looks to me that the 265/30 plus 275/30 Tire compliment really doesn't cost you much relative to the stock 235/35 in the Pilot Sport 4s. But it looks better and it's night and day in terms of traction at the limit. And as I've already mentioned and somewhat surprisingly there is no terminal understeer at least in my car with this minimally staggered Tire compliment. Highly recommendedI've had a chance to do more range and efficiency testing on the super wide tire compliment. It's a little bit discouraging, as I was expecting better results after the 275/30 addition at the back only really cost me about 5 Watt hours per mile compared to the stock 235/35. But the addition of the 265 / 30s at the front is probably costing me at least 8 watt-hours per mile. I'm a little bit surprised that the narrower tire is costing more than the wider tire at the rear but I suspect some of that is rolling resistance because this is not a Tesla spec Tire, unlike the rear 275 / 30. Some of it may simply be aerodynamic drag as well, as the rear tire is a bit more out of the air stream than the front tire.
In any case the combination costs me ~13-15 watt hours per mile, and this is relative to the stock Michelin Pilot Sport 4S Tire in the 235 / 35 20 inch size which is no efficiency champion. I'm reasonably confident that this is accurate because my wife's car which has the stock suspension, was just about 15 watt hours per mile less efficient, but we picked up five watt hours per mile with a front spoiler being added to hers. This meant that my car was just about 10 or perhaps 8 - 10 Watt hours per mile better than her car, and now with the addition of the much wider fronts, there's no difference at all. Still, even with the 13 - 15 watt hours per mile efficiency penalty for the combination of 265 / 30 front and 275 / 30 rear, I wouldn't go back. The handling is just in a different League.
Next tweak for sure is the @MountainPass front bushing. At least that won't cost me any range!