Me again -

Also, prior to the Jags I had a '98 SL500, with 16" wheels. Kind of a vintage (read: "dated") look. But that thing just glided along. Drove one the other day and had forgotten how smooth it was. I am a firm believer that the tire sidewall is the most significant part of the entire suspension system.

 

Found this information

With its Eaton supercharger, the XKR develops 420 horsepower at 6250 rpm, and 413 pound-feet of torque at 4000. It also rides more firmly than the standard model, with spring rates increased 38 percent in front and 24 percent in the rear; and its steering is tuned for higher effort and quicker response.

 

Steve - The description you posted is describing a pre 2010 xk with a 4.2 engine. My experience has been that the 5.0L XKs had a stiffer suspension than the 4.2L cars and that the 5.0L XKRs suspension is not that much stiffer than the NA 5.0L cars.

 

Ralph
I know Koko was mentioning that he was looking at the xk/car in the 4.2

 

For the 5.0 XK with CATS, will the XKR CATS shocks fit in my XK?

I'd like to actually stiffen up my ride.

Thanks

 

Question: Why can't you just put smaller wheels/tires on a new xkr? Will they fit? If you could put 18" on the newer models that would help out a lot on the ride.

 

18s won't fit over my brakes.

 

I sold a 2001 Mercedes Sl500 last year. It rode on 18" wheels and, surprisingly, my 2007 XK Convertible that rides on 19" wheels feels similar in ride quality.

I think the OP would be better off buying an XK with 19" wheels. Sidewall does make a big difference and as far as going with an XKR....that depends on where the car will be driven the majority of the time. If the car will be driven for touring then an XK is a good choice. (The XK is comfortable cruiser, not a bruiser.) If the car will be driven for spirited driving then an XKR is the one. Just hang on to your hat!

 

As far as I can see from the workshop manual, the shocks are the same on all 5.0 Active Dynamics cars (continuously variable dampers, different to the hard/soft 2-way damping on the 4.2 models). I expect the difference is in the settings programmed into the Active Damping Control Module. There are different springs on different models, e.g. the Dynamic Pack and R-S models have 30% stiffer springs. But you'd need to check part numbers to be sure. My car, with the same setup as the R-S, is certainly firmer than a standard XKR.

 

My 07 rides slightly better than my 00, and it's 20 vs 18 inches and lower profile tires. Condition of suspension and tire characteristics play a part but these cars ride well for what they are.

​​​​Honestly, drive various cars and form your own opinion. I was surprised how well my 07 XKR Coupe with 255/35R20 and 285/30R20 Continental DWS 06s rides.

 

So confused I thought all XKs had CATS?
How do you know if you have CATS or not?

 

I thought so too, but the workshop manual mentions standard and adaptive dampers - I've never heard of an XK with non-adaptive ones, though. But I believe any Adaptive damper will have a wire coming out of the top of the suspension turret.

 

Very early XKs in some geographies were available without CATS. How many were actually sold, who knows.

 

Deleted

 

Per your request: I had/have both an 07 xk and xkr coupe. The replies you've got mirror my experience. More than adequate acceleration for both. Both of mine were and are daily drivers. Much better fuel economy with the xk (>30 mpg on the highway vs 24mpg, same road for the xkr). Unless you're an aggressive driver and want to occasionally blow the doors off, the xk is a better all around vehicle.

 

I have an '07 XK and have been trying to find new front shocks with CATS to no avail. The XKR shocks seem abundant, is that a viable option? I assume there would be a ride stiffness change but only wonder about the electrical implications: Will it always give me a dash light or code, or will it always just be stuck in sport mode, etc? Anyone with experience trying this?

 

I can't think of a reason why they would not, but I suspect valving may be a bit different. I'd expect a slightly harsher ride....
2010 shocks or newer, which are fully variable, will work but you will likely loose the "soft" setting due to the different electronics.

 

Thanks for the input. I went ahead and ordered 4.2l (07-09) XKR front shocks and already have a set of new standard NA 4.2l XK rear shocks. I’ll give it a shot and report back.

 

I can confirm I have xkr shocks in ny xk.

Before installing please check your struts are not faulty by dimpls plugging into your harness it's not uncommon to be sold a faulty strut and much easier to simply exchange for a new one beforehand.

 

Thanks for the input on both points. It’s good to know I’m not starting a project that will cause havoc with the electronics. Additionally, I hadn’t considered new Bilsteins would arrive faulty but now that you mention it the NA XK rears that I bought arrived repackaged by the reseller and poorly at that. Surely it’s better to find out if they function prior to the install!👍