i got 17" adr wheels that have a 40 offset. does that mean the tire size i should get are 225-40-17? or do i have to get 215 like stock? if i want wider tires, what's the largest size i can get without worrying about doing damage?

 

If you look in the Sticky: Wheel Ftment you will see a 17x7 with 215/40/17s. He reported no rubbing or trimming and shimed the rear to give ET30 and even out with the fronts.
There is also a 17x7.5 with 215/40/17s. This setup has 3mm spacers in front shimed in the rear and he had to do some triming.

You don't say what your wheels width is but based on those two setups I would guess that a 225 tire will be needing spacers and shims and trimming.

IF you have 7" wide wheels the 225s will add .2" to the Inboard & Outboard over the 215s. If you have 7.5" wide then the increase is almost .5" increases over the 7" and 215 combination.

 

they're 17x7

 

With the 17x7ET40 and 225/40/17 my guess is you will be OK in the Inboard side and have some rubbing at full lock. You would compare VERY closly to the 18x7.5ET35 with 215/35/18 combination that reported some rubbing.

I would say no problems with 215/40/17 because you have only changed the ET by 5 which is usually regarded as within the stock wheel range plus you have steped down from 45 to 40 aspect ratio.

So, no problems go 215 maybe some trimming go 225.

 

the stock tire on the tc is 215-45-17. with the adr wheels, the offest is 40. so that means i would need a 215-40-17. would i be ok with a thicker 225-40-17? i have the trd springs right now, so the drop isn't too much.