Hi guys,

Quick question about rim and tire size. Got 18x7.5 48 offset aftermarket rims, with the stock tires, but I need to get new tire for the summer, and I can't choose the size.

I'm lowered on eibach prokit.

I was thinking about going with 235/40/18 tires (0,82% vs stock tires), but I know that the recommandation with those would be at least 8.0 inches rims ... I read that 235 would fit on 7.5, it have been done numerous times, but wouldn't be the best for auto-cross or tracks because the wall will loose some stiffness, but I won't do any of those.

Or is it better to go with 225/40/18 (2,07% vs stock) or 225/45/18 (1,39 vs stock) ?

helppp

thanks !

 

any tips ? :P

 

I think you will get more drip gains by going with a summer only compound in stock size rather than going wider on an all season compound. Going too wide for the rim leads to transition delays,, turn in... wait for the the tires to catch up..... thats not exactly what is going on but in general it leads to a mush feel.

In Most cases 235's fit well on 8" rims. Some OEM setups (E36 M3) use 235 on 7.5" rims, but if you look at the specs (on tire rack for example) each tire and size will give a section width, tread width, and measured rim width.... not all 235's are created equal. Dunlop Z1 starspecs in 235 are as wide as many 245's.

225-45-18 Z1 star spec shows a measured rim width of 7.5" with 800 revolutions per mile, where as the stock advans are 810 rev's per mile. 225-40-18 Z1 show 830 revolutions per mile....

8" to 8.5" width will give you a lot more options, I could not find any decent summer tires in stock size.