I am planning to take my P85 to the track this spring.
My son-in-law has a Caddy CTS-V wagon and is chomping at the bit to take me down.
My question is, am I better running my Bridgestone Pole Position 19" RS970 As, or putting on my summer 21" Contis that came with my car?
I've been running the 19" Bridgestones for the Philly winter and have been very pleased with them, although I was just told by Tesla that they are "non-approved" and were rejected by them during their testing due to their poor low rolling resistance.
Anyway, assuming we do our run on a day that is mid-60s-70F, which wheels/tires should give the the biggest benefit for the quarter mile at the track?
Surprisingly, you pretty much always get a slightly faster acceleration time with smaller rims and higher profile. A swedish magazine tested a Golf GTI with same tires but different sizes. 18, 17, 16 and 15". And the smaller ones got a couple of tenths faster from the one above. Assuming that your 19" tires are a similar compound to your 21"s, of course. If your 19" inches are allweather and 21" are pure summer tires, then I dont know.
If you are really serious, top the car up, bring both sets along to a deserted place and do some unofficial testing with both sets and a stopwatch :wink: