Right now i have 235 45 r17 on my lexus is300 but i am buying new tires and i was wondering if i could go to a 240 40 r17. the actual tire size stays about the same as stock i just add about an inch. i have no problems with the 235's on there but the stock tire size is 215 45 r17 so i dunno.

 

if its just one series up it should fit no problem.

 

this may be a cheesy answer but if look in a summit racing catalog where the tire and rim section is there is a area where it will tell u rim width and max tire width. I think u can go up to a 255 width.

 

Why such big tires?

 

well because my wheel wells are not as limited as most of yours. plus i am rear wheel drive now and would like to get as much rubber on the ground as i can especially with winter coming up. besides if i step it up to a 245/40/17 the actual overall size of the tire is almost identical as stock where i am almost an inch taller right now. so if i keep the tire as close to original size but add some width it will perform a little better and keep it looking stock.

 

Oh, i must have overlooked where you said this was going on a lexus. I just assumed you were talking about an integra. BTW, i think narrower tires are better for winter... for driving through snow anyway. You probably don't get that in Utah though, so nevermind lol.