Largest Wheel Width For 18 X 8 Rims

[SouthDakotAlero]

Does anybody know what the largest width tire I could fit on an 18 x 8 rim is? I don't want to know if it will fit on the car, just if it will fit on the rim.

[mfuller]

Depends what the aspect ratio of the tire will be.
For instance, if you will be using a 40-series tire, the generally accrepted max tire width is 245mm. 50-series tire you can likely move up to a 255mm tire.

[Oldsman]

255 would be the widest for 18x8