So as I'm pondering summer tire replacement brands and sizes I keep coming back to Coventry Hornet wheels. I really like the look of them on this thread:

https://www.jaguarforums.com/forum/x...40/#post640202

My preference is for the Hyper Silver finish. But they are available in a myriad of sizes and widths. I don't want a gansta looking Jag, so I'm only considering 17" or 18" wheels. The Coventry specs are as follows:

17x8, 5/120, 25 mm offset
18x8.5, 5/120, 30 mm offset

The 17x8 wheel is the same as factory, so no troubles there. By my calculations the 18" wheel will have the inner face 8 mm closer to the inner aspect of the car, and outer face likewise will be 8 mm closer to the fender. This shouldn't cause any issues, correct?

What tire sizes can I use on the 18 x 8.5 wheel? I'm considering 235/50-17 for the factory size to reduce tramlining. I don't mind increasing the tire diameter as it would improve the speedometer's accuracy. Stock diameter is 26.04." 245/45-18 tires are 26.68" in diameter; 255/40-18 are 26.03." Can I go any wider than 255? My thought is if 255 was too wide for the factory 8" wide wheel, 255 might be just right for an 8.5" wheel.

What do you gents think?

 

Std XJR tyres in UK were 255/45/17 so 255/40/18 would give you almost identical rolling radius. Thw wheels had a 33mm offset, so I suggest that you aim for something similar so as not to affect the steering or clearances to the body and chassis.

If your car suffers tramlining, I have found that can be much reduces by uprated front top wishbone bushes. Other owners have found that adjusting wheel bearings helps as well.

Several tire websites can confirm what tyres diameters/width/aspects ratios fit properly with which wheel widths.

 

Andy, what do you mean by 'uprated' front top wishbone bushes? Still rubber, or polyurethane? And who sells them?
I am having mild 'wandering' issues, as well as a bit of tramlining. My local experienced Jag-trained mechanic recommended against urethane bushes as it will change the feel of the suspension and lose that lovel Jaguar ride.
What do you use/recommend?
thanks, Al NZ

 

Thanks for the advice! I've had many bushes replaced in January. I'll have to see if those particular ones were replaced. I'm using Yokohama winter tires on 16" XJ6 wheels for winter right now. Ever since installing these the tramlining has gone.

The 18x8.5 with 30mm offset sounds like the right wheel. Thanks again.