Has anyone run 235/40 tyres on a standard GTB 18" rims????

[PoidaGT]

Hey Guys

Looking around for tyres at the moment.

Not sure if 235/40 tyres will fit and work properly on the standard GTB 18inch RIMs.

Has anyone tried this??

Feedback???

[HyRax]

They will work fine, though there will be a 1.3% difference in your speedo (will read faster).

[paggaz]

235's will be too wide on a 7" wide rim... Yes it'll mount on the rim but when inflated, it'll bulge on the centre of the tyre giving you quicker wear in the centre and less surface area contacting the ground. Found this out the hard way with my old forester, mounting 235/40 on a 17x7" rim and only ended up getting less than 30k kms on them before the tread depths in the centre of the tyre were no longer roadworthy.

Better off going with 225/40 (slightly smaller than stock) or 225/45 (slightly larger)

[HyRax]

I thought the GTB rims were 7.5" wide??

[paggaz]

Nope I'm pretty sure the TBSTI wheels are 7.5" wide, but the GTB rim specs are 18x7 +55.
That's going off the top of my head, happy to be corrected

[HyRax]

Ahhh no I think youre right. Got them mixed up.

[BJ]

paggaz is right, the car won't corner as fast and your tyres will wear out in the middle.

[PoidaGT]

Thanks Guys

That clears it up for me. 225/40's for me!


I measured my GTB rim and it was approximately 200mm from outer edge to outer edge. This is a Bee's Dick under 8inches ???
It must be measured from the inner edges of the rim.

[bigBADbenny]

Yep inner edges...