gaspam

anyone else have issues with traction control being triggered when going up to 275/35 on stock 18's and leaving the stock 235/40 tires the same?

just got new 275's in the rear and tc keeps coming on and now it just disabled itself and gave me the "traction control unavailable" warning on the dash.

I thought the ECU's variance for front to back tire size diff was like 2% or something so 235 in front and 275 in back shouldnt be causing any ecu issues

whoover

A 2% variance between expected and actual tire diameter is enough to make the ESP think you're in a skid. When changing tires you should match rolling circumference within 1% at the worst. .5% is considered the desirable target.

The theoretical +2 fitment for a 255/35-18 is 275/23-20, which of course doesn't exist. Even a real-world 275/25-20 has a circumference variance of 1.5%! Note that the factory 19" option uses 255/30-19, which is an almost perfect circumference match but isn't any wider than the 255/35-18. It has a little less rubber so will be a little more tight-handling, but the factory doesn't offer a wider option because there is none with the same rolling circumference.