Only have experience with 19" wheels on 05 XJR. IMO stay with the 19". The ride is firm enough already and curb rash , as bad as it is with 19" wheels, will only get worse with 20" wheels and that will break your heart.

If you don't like your present 19" wheels, there are an infinate number of alternative wheels to choose from.

AS an aside, the XJRs I have seen with 20" wheels look a bit strange. IMO.

 

I dumped the 20" wheels my car came with because I just couldn't stand the very harsh ride thye gave. (car is also a 'Sport' which is harder springs anyway). I now have 18". I don't think Jaguar got the suspension setup right for the larger sizes on the X350 model.

Maybe the 20" are OK for going round racetracks but I don't do that too often ! In the UK our roads are awful and getting worse.

 

I have 20" on mine https://www.jaguarforums.com/forum/a...p?albumid=1258 and while I didn't like them at first I've grown accustomed to them but with the roads the way they are I'd feel a bit more comfortable with 19" ones (first day I had the car I destroyed one wheel by hitting a pothole on the freeway) I do get lots of compliments on them though

 

Those large diameter wheels combined with the low aspect ratio tires are the absolute worst trend in automotive technology. They will hopelessly degrade the ride quality for cars that were famous for their silky rides, such as the XJ cars.

I have 3 cars that came with low aspect, high performance tires on wheels, 17" and 18". The common denominator is that I am running 26-27 lbs of tire pressures in each car in order to make their ride half acceptable on those horrible California inter-city freeways. Still the ride is nothing like it should be on a fine car, like my '05 XK8 Coupe. I'm seriously considering going against the silly trend and get SMALLER wheels/taller sidewalls for my Jag and regain the silky ride quality while still have far more cornering power than usable under any street driving conditions. I'm also seriously considering the purchase of a new 2011 XJ but, I think that even the base 19" wheel/tire is unreasonably harsh. I'd like nothing larger than 17" for the XJ, which would give one more inch of sidewall flex between the road and the car.

BTW - if you worry about my lower tire pressures, don't. I track raced cars for decades with cold tire pressures as low as 14 lbs in slicks with much higher aspect ratios and softer sidewalls than the present crop of performance street tires. They really will not roll of the rims, no matter how hard you corner.

 

axr6,

Hear, hear, ditto, right on and you didn,t even get into the curb rash and road damage issues. You can absolutely trash a 19" and 19" plus wheel on a speed bump or minor pot hole.

 

I wouldn't worry about the tires coming off the rims. I would worry about denting the rim or uneven tire wear.

 

I have 20's on my xjr. If you live in a area with nice roads, go for 20's they won't hurt. If you live in a big city like i do. You will regret it. I love my 20's but im not going to upgrade my rims bigger than 18's maybe 19 max, ( if my future car permits). The ride on the 20's is very harsh

 

Have 20" wheels on mine (from factory) and ride is superb (comfort suspension)
I like to put my foot down (hence the remap) and drive around roundabouts quickly now and again and no problems over uneven roads either.
That said the ride would be firmer with the R suspension.