I am looking to get 18" wheels for my 06 TL. I want a bigger wheel (better looks) with much better handling without affecting the speedometer/tach reading too much.

I compared different tires on 18" wheels and found that the closest to stock 17" diameter is what they put on a-spec 18" wheels...235/40/18. The speedometer will read .03% slower...when the speedo says 60 mph you are really going 60.2 mph.

I found that the next closest to stock is a 255/35/18 which I prefer. The speedo will read 1.2% too fast...when the speedo says 60 you are really going 59.3 mph. Although there is a slight difference in diameter, it really won't affect the speedo/tach reading too much (12miles less per 10,000mi). Also, the tire is 255mm wide > more tire on the road = better grip?
Plus a thinner side wall (3.7" a-spec vs 3.5" 255's) > stiffer sidewall = better handling?


Has anyone ran a 255/35/18? Any rubbing? what offset?

Will the 255 handle better or is my logic wrong?

This will probably be on a 8.5" wheel.

 

You did your homework. I just don’t agree with logic: stiffer and smaller sidewall means better handling. It brings more direct feeling, but doesn’t make car faster in curves. Look at racing cars. Any shallows?

 

I have the 04 A-Spec 8.5" rims and up till this last set I went with the OEM 235/40/18's.

I've since had my rims reconditioned back to new and put BFG G-Sports 245/40/18's on. The tire sidewall is now straight with the rims edge.

I'm going to go 255's on my next tire now that I have the 245's. I guess I'll go 255/35's like you are wanting. It'll be interesting to see if they will rub.

 

I'll have to do some more research to see if they'll fit. I was doing this research on a 9" wheel...wheel distribuotrs said it would rub, but I bet an 8.5" wheel will keep the 255 tire in tighter.

do you have the stock a-spec suspension? If so, how does it handle?