these are the wheels I have on my car right now:

http://www.tenzoracingsports.com/roa...-10/index.html

18X7.5
I am running hotchkis springs right now (almost 2" drop)
I have 215/35Z/R18 84w now can I go bigger?


what is the largest size tire I can put on them?

215/40?
225/?...etc

 

225/35/18 should work fine and be within spec. of your stock diameter. Bumping up to a 215/40/18 puts you just outside of spec.

 

I have 215/40/18's on mine they are 3.8% larger in diameter. They clear a 2 inch drop with no problems except My wheels are a 42Mm offset so mine touvch on the inside front on full lock turns not a big deal and they barely rub at that. The ride is significantly better than a 35 series tire. I noticed no real performance hit on my manual due the diameter increase (I just remember to factor in the 3.8% if I want to see MPG). I recommend the 215/40 highly.