I have probably an unusual question but bare with me. I have a 2004 XK8 convertible which I have had for 3 years. It is well maintained and reliable, we have no problem heading off on a 2000 mile trip, I think it is in excellent shape. I have always found it pretty peppy and I know it is a Grand touring car and not a sports car so have driven it like that. I live in Canada and only drive the XK8 in the April to October season. Last November I got a 2008 Jag S-type for a winter driver and because it has the same power train as the XK8 I fealty it was a good fit for maintenance and because I like my jags.
My question is, is it normal that the S-type feels sportier than the convertible. The brakes on the S-type are much more responsive, and the acceleration on the S-type seems much sportier and lighter. I wish the performance of the 2 cars was reversed. Anyone else have a similar experience. I guess I should drive another XK8 and see if mine is nominal.

Summer joy and Winter beater.

 

The s-type is based on the old Lincoln ls, x-type back there is of a ford mondeo, and the XK8 is from a the old XJS's. All very different cars, the XK8 is the real deal in this pic. The rest are various forms of brand engineering by Ford motor co to save dollars

 

I am well aware of the pedigree of the cats, and I worked for Ford during the period when they took over Jag. I used to tell some of the execs that finally they could get a company car that was actually a luxury car. My question though is still is it normal for my S-type to be quicker feeling then the XK8 with the same power train?

 

Before I bought my XKR, I was really looking into the S-type...
Perhaps it is the Supercharged R Version S type?
That one has 390 HP and I believe a different braking package...
The Xk8 has only 280 HP...
Big difference in "pep"

 

When I got my 2004 XK8 I still had my 2005 XJ and I had the same feeling that the XJ was faster.

I solved the issue by doing the throttle cable adjustment on the XK8. After that the XK8 was very comparable. Perhaps you can try that and see what you think.

From the Rev's library of videos

I also remember reading that cleaning the MAF can help a bit too.

 

Not helped by knowing little of S-Type . . . suggest you pin full details of both into your sig.

The MY04 infers 4.2L V8 NA. Is the S-Type also the same, with identical 6HP26. What about diff ratios? Rolling radius of rears? There are so many variables, I suggest you check before chasing what may be ghost issues.

Cheers,

Ken

 

I do like the dark blue metalic

 

The X-100 platform looks so much better, I doubt I would even care if the S type was quicker...I know which I'd choose to drive .

 

I would second the suggestion to check the throttle cable adjustment. My car came with it "loose" and the car felt somewhat unresponsive and "heavy", especially off the line. That zero-dollar adjustment brought the car back to life.

Separately, you can look into upgrading the front brakes on the XK8 to the XKR level. Not entirely cheap or painless, but can be done. Of course. bleeding the stock brakes and looking at a more aggressive pad would do, too.

Last, check "the numbers" with an ELM327/Torque Pro. Maybe your air flow meter is aging, and giving you crappy readings (that the engine can compensate for, to a point), leading to so-so performance. Are you using high octane gas?