Ok, i've mentioned that i'm having major traction issues with the power it's now running.

 

I've looked at the used alloys i bought and to my surprise they are 10's on the rear which i can't believe as they are currently runnig 255's so luckly i will get a decent grip with the right tyres

 

 

The fronts are 17x8jj and the rears 17x10jj which are pretty big and currently have 255's on them.

 

Not many manufactures make tyres over 265 for a 17" and i need as much traction as possible.

 

Toyo go upto 265/40/17

Verdestein Ultrac 275/40/17 and a cheaper option Falken FK452 275/40/17

Kumho ECSTA Sport 285/40/17 cheaper than all above.

 

Initially i would go for the largest being the Kumho but just because they are bigger don't mean they will provide more grip as they could be crap, Toyo i would get if they were bigger and Verdestein are meant to be good but very expensive as for the Falken they are fairly priced but not sure what they are like as a tyre.

 

And what about the fronts? stick to what's currently on there? 225/45/17 or go for a 235?

 

Also what about the profiles? would a different profile be better instead of 45 front and 40 rear?

 

As much info and help as possible please as it's currently dangerous to drive, spinning in 4th/5th is scary :shock:

the profile is % of the width, so the wider you go, the lower the profile number to maintain the same rolling radius, also the same width tire on a 18" should be a lower profile than a 17" to make up for the alloy being larger.

So with 17", 235/45 and 275/40 sounds about right.

Did you check your offset for the rears to make sure 275 will fit without rubbing?

The best tyres I have ever had were the Toyos, but I now have the Falkens and can't really complain about grip. plus the price is good.

 

There is a link on here somewhere to a site that provides calculations on side wall versus width. I think I saw coopers swb put it up...

http://www.tyresave.co.uk/tyresize.html

the profile is % of the width, so the wider you go, the lower the profile number to maintain the same rolling radius, also the same width tire on a 18" should be a lower profile than a 17" to make up for the alloy being larger.

So with 17", 235/45 and 275/40 sounds about right.

Did you check your offset for the rears to make sure 275 will fit without rubbing?

 

I think that 275's may require having to have the wheel arches rolled to prevent rubbing if it is a standard 30 offset.

 

Also I had those Verdistines on my RICA T5 R fire engine and they were really good. Best tyre i've ever had on the Volvo T5's but couldn't get hold of them easily. As Pete has said there are lots of different tyre compounds and getting the right one makes a world of difference. I swear by Bridgestones S02's for the Z and if I can't get then then I'll go for Mitchelin Pilot Sport or Cintinental Rain Sport. Problem is that like you said most firms only make tyres up to 265 on 17's but that is wide enough if you have a good tyre unless your running 600 RWHP.

the profile is % of the width, so the wider you go, the lower the profile number to maintain the same rolling radius, also the same width tire on a 18" should be a lower profile than a 17" to make up for the alloy being larger.

So with 17", 235/45 and 275/40 sounds about right.

Did you check your offset for the rears to make sure 275 will fit without rubbing?

 

i don't know how to check the offset, today i took a hack saw to the hicas bar and took the lil nobble bit off which was catching on the wheels, they are a much better fit now.