hx_guy

I bought some 18x8 wheels off eBay and am trying to figure out which tire size to go with.

Stock: 225/55-16 = 25.74" overall diameter

Option 1: 225/45-18 = 25.97" overall diameter. Fits rims 7" - 8.5" wide.

Option 2: 245/40-18 = 25.71" overall diameter. Fits rims 8" - 9.5" wide.

I want to go with the 245/40-18 but are they just a little too wide for 8" wheels? Seems to be right at the limit whereas 225/45-18 falls right in the middle.

Dexion

Well first off you'd want 18" rims with a 40 profile tire, if you go 45 the speedo will be off, among other things.

hx_guy

The tire profile is a result of the tire width...it's a percentage of it, so a 45 series tire can be the same height as a 40 series if the tire is narrower. As you can see in my examples, the two are within a 0.25" of each other...or 0.112 top and 0.112 bottom, I doubt that's an issue (think of a new tire vs used, it uses more thread thickness than that).

My cornern is more the width. Basically will a 245 wide tire look funny on an 8" wide wheel?