Changing from 17" to 18" wheels

[Wheelspin]

Several posts in this section have commented on the difficulty of finding 17" tyres. As 18" wheels were also fitted to this model (mine is 1998) and have much better tyre availability, switching over looks like a feasible option. The 18s seem to have slightly wider backs and I know the XKRs had some different styling but I'm assuming all 8s and Rs of this early period are interchangeable. Has anyone had any problems with this before ?

[mike020150]

Changing from 17" to 18" wheels is an easy change. There are plenty of Jaguar wheel options available second hand. The fronts are 8" x 18" and the rears are 9" x 18". The respective tyre sizes are 245/45R18 and 255/45R18. Simply take off the 17" wheels and tyres and bolt on the 18" versions. That's all there is to it. 'Comfort' tyre pressures should be set at 26psi front and 28psi rear. Mike.

[DaveO]

Does that throw the speedometer accuracy?

[mike020150]

No, because the lower profile of the nominally larger diameter tyres means that the rolling radius stays approximately constant. Mike.

[RMA37]

I'm always a bit confused with XK8 tyre pressure recommendations as the range is quite wide. Mine are 18inch, fitted from new and have the recommended Pirelli tyres, but when I put the 'comfort' pressures in they look too 'bulged' on the road. That must increase fuel consumption and possibly increase the wear on the tryes. I opt for mid pressures, rightly or wrongly, but the car handles very well.

[gts]

If you haven't changed your wheels the 17" Pirelli P Zero tyres are available now. Just changed mine two weeks ago.