Can anyone tell me the reasoning behind the front tire 255/35R20 being a taller profile then the rear tires 285/30R20? On other rear wheel drive vehicles I have owned with offset wheels the rear tires were alway both wider and taller profile then the fronts. It looks strange to me and the only reason I can come up with for Jaguars factory sizing would be maybe to balance overall wheel weight for all wheel drive models. Unfortunately I'm not an engineer and am not qualified to make a decision on changing the profile sizes to be more ascetically pleasing. Anyones input would be appreciated.

 

I've moved your question from General Tech Help to XF/XFR forum. Members here with the same model will be able to advise.

Graham

 

I'm pretty sure it is to keep the diameter of tyres as close as possible.
Exactly why they feel the need to do this I don't know, maybe something to with the DSC system which could be upset or triggered by only slightly differing rotational speeds front to rear. If the rears were both wider and taller profile they would be significantly greater diameter than the fronts.

 

Actually if you use a wheel calculator, 245/35 and 285/30 are closer in size. I have know idea why they went with 255 in the front.