I will be replacing my Michelin Pilot Sport 255/40x18's very shortly. I want to get rid of or, at least reduce the tramlining and I have researched 235/45, 245/45 and 235/50. I have the 8 inch wide asteroid wheels.

The 235/45 will have a 1.2% change in speedo and odometer readings, a sidewall height increase of 0.15 inches and a circumference increase of 0.9 inches

The 245/45 will have a 2.5% change in speedo and odometer readings, a sidewall height increase of 0.32 inches and a circumference increase of 2 inches

The 235/50 will have a 4.7% change in speedo and odometer readings, a sidewall height increase of 0.6 inches and a circumference increase of 3.8 inches

All the tires I have looked at have had a higher maximum load rating than my current tires, a speed rating of W (270 Kmph max), and have a rim width range that includes 8 inches.

Has anyone put a smaller width or higher aspect ratio tire on an XJR? Does anyone have any recommendations on the tires sizes above? Would the 235/50 be too much of a change?

Any input or suggestions would be appreciated

Thanks

 

255/40/18 is too wide for the 8 inch rims as they come from the factory. I guess they did it for more comfort. I've used 245/40 as well as 235/45 winter tires. Both these sizes are better than stock.
Don't use the 235/50. If the 235/45 is already taller that stock, the 235/50 is more so.