UK300-199

Hi

Ive got a UK300 Which has 225/40/zr18 on the vehicle,but the tyres have worn out so i can get some tyres of my mates RX8 They have 225 45 18 what is the difference between the two,i mean handling wise and stuff like that?

Any help will do.

Thanks.

BlueBoy

I would think, the main worry is rubbing on the arches with the increase in profile. Your speedo will be out as well.

As for handling, there won't be much difference I wouldn't have thought, although the 45's don't look quite as nice on the car IMO

UK300-199

Thanks for your prompt reply,

When you say the speedo will be out what does that mean?

ozzy

When you increase the profile of the tyre, you increase it's overall rolling diameter. Since you speedo is calibrate for the diameter with your alloys + 225/40/18 tyres, any deviation away from this will cause the speedo to over or under read.

There's a calculator on this website

Given the tyre sizes you mention, when your speedo reads 70mph you'll actually be travelling at 72.47mph. This is assumming your speedo is accurate in the first place.

Normally when people change profiles, they also change tyre widths to compensate (as the tyre profile is a percentage of it's width).

BTW, 225/40/18 is the correct size for a newage.

As for handling, then you'll notice more depending on the make of the tyre more than just the profile - unless the are the exact same brand as fitted to your UK300.

Stefan

BlueBoy

All said without me opening me mouth - I'll keep it shut now as I couldn't have said it better than Stefan

UK300-199

Thankyou for your reply and apologies for the long delay in replying.

Ok So there wont be a hell of a difference then will there it wont damage my car or anything like then its fine.

Thanks once again.