[2023_ZL1-AUTO]

Originally Posted by arpad_m

You are about to go from 305/30/20 to 345/30/20, which increases tire diameter/circumference by 3.3% while leaving the fronts stock.

In many cases people saw Stabilitrak, traction control and/or ABS weirdness when exceeding a ~3% margin of difference between front and rear with these size changes, so I would not recommend this plan. To be on the safe side, either increase the height in the front as well, or go a smidge narrower in the rear.

Of course if you're hardcore and keep the nannies off all the time, you may chance it, but I don't think that's a good idea even then... taller tires can improve max speed but are worse otherwise, and your rears would be at ~28.1", almost an inch taller than stock.


EDIT: one more thing, those Toyos whine like a monster truck (been there, heard that, sold them), so unless your setup is super loud in the cabin, it may well have bothered you, so don't feel bad you had to forgo them

Good info! OK, this is why I post my "dumb" questions here. I know I'll get answers from those who know their SH!! I don't want a taller tire, never thought of how the tire numbers worked together like that! I didn't want to change tire size in my computer, although I have HPTuners so I could. I would just rather not. Thus, maybe should go with 325/xxR20, and try to keep same over all height somehow? Wider in the front I'm not a opposed to. I just didn't need to change them to "change them"! Thanks again for the info!!!!