I've owned XJ's for over 30 years. Last year, my friend & mechanic convinced me to swap my 2002 VDP for a 2009 XF Supercharged. I knew it was a mistake, but I did it anyway.


After one year, I find myself loving everything about this car -- except the ride. It's not quite as rough as my wife's XK, but I feel everything in this car, and I simply don't want to. I want my XJ ride back (or, close to it).


Like my wife's XK, this car has 20" rims with low profile tires. It had some questionable Sumitomos on it, and I've already replaced the fronts with Continental DWS 06's. It's quieter, but still a very stiff ride.


Before I give up and get rid of the car, I'm wondering how much of a difference I can make by installing 18" rims with tires that actually have some sidewall. Does anyone know if that will materially smooth out the ride, or am I simply feeling the effect of a stiffer suspension and shorter wheelbase than what I've enjoyed on my XJL and VDP?


Thanks,
Doug

 

Unfortunately 18's will not clear the larger brakes on your Supercharged model, you can go down to 19s though. I too would like to go smaller than my current 20s for a better ride but for me it's just not worth the money at this time.

 

Thx BlckCat; I didn't even think about the brake clearance. Any confidence that I would actually notice a difference if I swapped to 19" rims? I don't have any experience with standard profile vs. low profile on the same vehicle. My wife's XK rides hard, but every XK I've driven has low profile tires on them, and I've never driven an XJ with low profile tires.

 

you might be able to change the shocks to the base/premium model. those cars ride nice, and what you are experiencing is why i went for the non-supercharged models. the naturally aspirated V8 is extremely satisfying and powerful.

come to think of it, you might be better trading your 09 supercharged for something like an 11 non-supercharged. you can do a trade for a newer car and not spend much if anything. changing wheels/tires and suspension can gets expensive.

 

Thanks again. Swapping vehicles is distasteful; I know this car's warts, and its history. And the sales tax I have to pay on a swap would cover a fair amount of improvements to this car's ride.

 

I was talking to my mechanic (not a dealership mechanic) about the ride on my 2009 XF Supercharged, inquiring about what I might be able to do besides swap out the wheels & tires. He noted that the shocks are comptuter controlled, and mused that a Jag service guy might be able to reprogram the computer to soften the ride.

Anyone know if that's true, if it's been done, or if it's against Jag policy? Any chance a non-dealer mechanic might have the computer interface to do it?


Thx,
Doug

 

Unfortunately you are in one of those stupid states that doesn't give you a tax break for a trade it. Simple solution -- move to a normal state.

And getting a reliable NA 2012 XF to replace the teething-problem-prone SC 2009 would get rid of a lot of warts.

But do what works best for you.

 

'Teething problem'?

 

I think the 19s would make quite a difference in ride going by what people have said going the other way. An extra inch of sidewall is quite a lot of extra suspension in itself.

A softer spring rate would do it if the wheel size wasn't enough and won't break the bank. I wouldn't think it would be necessary to change the shocks.

 

I didn't want to swap out the shocks; just reprogram the computer for a bit softer ride. If possible to do, that would presumably be dirt cheap, esp. compared to swapping out the springs. No?

Anyway, anyone know if the shocks can be reprogrammed to be a bit less stiff?

 

Yes I agree. It reprogramming is possible that would be ideal.

If not a softer spring is the cheapest option followed by wheels and tyres. (although if you went to good used 19s you could probably swap your 20s because the 20s are more 'desirable'. I'm sure there'd be a lot of owners with 19s that would jump at the chance of a straight swap- you could even make a bit on the deal.)