Is it ok to swap tyre size to 225 40 18 from OEM?

[nugsy]

Hi guys im trying to find Kumho ku31s in Oem but cant get them in stock at the right price but can get 225 40 18 will this affect the car at all?

[tangcla]

Standard is 215/45/18 right? It'll be fine.

Stock size is 650.7mm; new size 637.2mm

This is within the +-15mm rule. Your speedo will be 2.1% too fast.

[whitedog]

+1 Im running 225 40 18 Federal 595 RSR semi slicks on MY07 GTB wagon, they are brilliant. The wider tyre also offers more rim protection than the standard 215.

[Hobber]

There is an info thread:

viewtopic.php?f=12&t=8756

Specifically the link to the "Tyre/wheel sizes and offsets that will fit on a Liberty"

as well as an online tyre dimension comparison applet:

http://www.miata.net/garage/tirecalc.html

which combined are great resources.

[adhar]

That tyre is technically designed for a 7.5 inch rim, and OEM is a 7 inch wide rim (unless you have STi wheels).

That being said i'm running the 225/40R18 Kuhmo KU36's on the OEM 18 inch x 7 inch wide rim with no problems.