SimonJM

Dear all,

Currently got standard 225/45 tyres on my 7.5 x 17" wheels.

I am very shortly going to need 4 new tyres and was wondering about putting wider tyres on.

According to their web-site Toyo T1-R's 235/45 and even 245/45 fit on a 7.5" rim.

I know this will make my speedo underread by 1.4% or 2.8% - not a problem as it currently overreads by 4%.

Will increasing the tyre width make any noticable different to grip?
Logic tells me that in the dry it should, but in the wet my actually reduce grip (more likely to aquaplain) as it is more difficult to expell surface water.

Any problems with a wider tyre rubbing?

Any problems with handling, road noise etc that I need to take into account?

All wisdom greatly received.

Cheers

Simon

SimonJM

TTT

DJ140

I was thinking of doing the same and another question to add to yours, would it increase the weight of the steering, which IMO is too light on the 03MY WRX?

BlueBoy

I should think there'll be a very "careful" way that they word it on the website if they say 235 and 245 tyres will fit on a 7.5 rim (perhaps something like - check it first as these are guidelines). I think the 235's will be certainly stretched on 7.5" rims and I can't see how the 245's would fit at all, after all I run 8" rims with 225 tyres on.

As a guidline for the 235's - the new MY05's have wider arches for the 235 profile tyres, that must say something about the fitting and I think your probably going to have to be a Richard Burns driver to get more out of a 235 than a 225 in my opinion.

I'd stick with the 225's really, there's less rim protection for you with the 235's stretched, there's a chance of rubbing on the arches and although they are an Evo standard size, they may cost more than the 225's.

mabelcable

hey there, you should check out this guy's website as his "wheel and tyre bible" is very informative and basically tells you what fits what.

www.chris-longhurst.com

BMW used to use 235/40/17 on their M3 GT front rims which were also 7.5 wide.

hope that helps

SimonJM

Excellent link.

Think I'll be sticking with standard size - at least there won't be any handling / rubbing problems.

One interesting thing on the site is that he recommends tyre pressures of 40psi
Using the logic on the site that would certainly reduce the contact area with the road and therefore grip

Simon