Got my first Jaguar late last year, 2010 XKR 5L SC. Don't think I've ever enjoyed driving a car around so much - in fact I know I haven't.

Couple of questions hoping perhaps someone could help me out with.

Any recommendations on tyres, suited for hot weather. I live in Oman, the hot weather really degrades them quick.

I've read some on this fuse 19 modification, is it applicable to my model? I wouldn't mind a bit more noise at the lower revs which I understand this would give me?

I have an issue with the front interior driver side ceiling light going on and off. Quite annoying, anyone know the fuse I could pull for that to just turn it off?

Suddenly owning a powerful car and I'm wanting more, having read some on engine tuning if I were to do that would I need to look at the intercooler as well operating in such hot weather?

Now I'm going to sound like quite the newbie but is it normal for the car to suffer from a bit of oversteer? The back steps out a little, which I of course have probably played with having got use to the handling. Just didn't know if this would be something that got worse if my tyres were performing badly.

Anyway, lots of questions, appreciate any advice. There are hardly any Jaguars out here and the dealer is less than efficient.

 

I believe fuse 19 does work for your XKR. Its located between the back seats. Yes good tires are more imortant on a XK than any car I have ever known. The car struggles to put the power down to begin with... i would not recommend ANY further power...but to each their own. The best tires Michelin Pilot Super Sport tires.... but getting them in the correct size is proving challenging. I have heard the Bridgestones Pole Positions are good after that for a close 2nd place??? Am I getting the name right?

 

Correct on Fuse 19, sounds great. Michelin Pilot SuperSports are OK, but not any of their other models. To increase power, don't bother. There isn't any verified good tune, and those that have supposedly done the PULLEY AND TUNE upgrade don't actually end up with any more power. The Jaguar ECM evidently isn't a friendly one to fiddle around with, and all the other modules counteract any changes made. Pretty much the same with exhaust changes. You may end up with a better sound, but negligible improvement at best. Air Intake, again don't bother. The dual air boxes get the coldest and cleanest air they can right where they are. You'll just have to be happy with the 510 HP.

 

Pulling Fuse 19 just leaves the active exhaust system valves open, which actually makes it louder between 1100 and about 4000 rpm, not at low revs (they're always open at low revs). If you want to hear how it will sound, just put the car into Dynamic Mode, which also locks the valves open.

The XKR has more torque than it can transfer to the road, which is why it can be a bit tail-happy. Fortunately, the sophisticated Active Dynamics system is very good at controlling that and keeping you in a straight line. On a damp motorway, mine will step sideways at 70 mph if I give it too much throttle, before AD catches it - it will spin the wheels in pretty much any gear.

 

Thanks guys for the responses.

Currently got Dunlop Sport tyres on the car, there is only one place that do Michelins here, will give them a call. They seemed hard to get hold of.

Glad you're describing how I find the car. When I first got it and was perhaps a bit too eager often found it difficult to get a lot of power down on the road when first taking off, but the next phases where very good. Definitely have had the wiggle of the tail but have found with time more predictable and have it happen less.

 

Bridgestone S0* Pole Positions are worth looking into. Their flagship tire and costs less the Pilot Sports.

 

I assume by degradation you mean loss of grip. Personally I'd get a tire designed to work at high temps like Nitto NT01's since it never rains in Oman. No tire is going to last (wear wise) when the asphalt is 180 degrees F and you drive aggressively. At least with the Nitto's you'd have grip at high temp. I'm sure there are other road use approved road course race tires that would work.

 

I believe the XKR-S GT uses Pirelli P-Zero Corsa tyres, which are a road-approved semi-track tyre. Like any of the 'sticky' tyres, they'll wear faster than the stock tyres.

 

Actually, there is plenty of evidence that a tune and a pulley give substantial power and torque gains on this engine. Search on this site for ECU tunes. Many enthusiastic reviews, for at least a couple of different tuners (ETG and Eurocharged, mainly). Some have posted before and after dyno numbers, as well. As I recall for just one example, Matt in Houston, who tuned an XKR-S, the engine of which is mechanically identical to the XKR engine, was particularly pleased with his results.

A couple of threads to get you started:

https://www.jaguarforums.com/forum/x...upgrade-64589/

https://www.jaguarforums.com/forum/x...y-combo-98134/

I did the pulley and tune from ETG, and have been quite satisfied with it. Did not dyno before and after, but several have. Felt distinct difference from about 3000-3500 rpm up to redline, and it turns out that is where I was supposed to feel it, from subsequent dynos provided by others.

This is a different question from whether it's "worth the money" or how usable the extra power is, because the limits of traction are real at these torque levels. In my experience, with correct modulation of the throttle, enough of the extra power gets to the ground to make it "worth it", but YMMV, of course.

 

Thanks. From what I have read around a tune does yield tangible increase in power. As you say though, actually using it is another matter. I've not exactly felt the need for more power but I do wonder if I'm lacking some grip at the moment which is holding me back.

 

I'm fitting slightly wider tyres to the back of mine this week - 305/30 to replace 295/30. However, that's only a 3.4% increase, so I doubt it will be noticeable.

 

I've looked at the XK/R threads as they don't necessarily have the same exact ECU as the XFs & XJs, and the consensus is that sometimes the dyno slips from the shop doing the work shows an improvement (imagine that) but mostly the people getting the work done don't actually notice any improvement in real driving.
https://www.jaguarforums.com/forum/x...-5l-sc-111917/
If you personally got some added power and performance, I'm honestly happy for you. That doesn't seem to be the norm, however.

 

I think that is not a fair characterization of those threads, and the experiences reported, with and without dynos, by those who have tried the tunes and pulleys with the tuners I mentioned. In fact, I cannot remember any significant number that didn't report significant power and torque gains afterwards, on paper and in the car. Those who dyno'ed their cars were very careful, as I recall to be present for both before and after dynos. If there was funny business going on with the tuners, as you imply, than it happened right under their noses.

The threads and posts speak for themselves. You seem to be a skeptic, and of course you are welcome to be one. But saying that "mostly" the tunes did not increase power, or that my increase in perceived power is "not the norm," simply does not accurately characterize the posted experiences of our members who have tried engine and pulley tunes available from the two tuners.

 

It's fair to counterpoint on tunes so folks don't go tilting windmills with their money.

I have no dog in the race, but am skeptical about trying to add more power/torque to a model that is well known to have problems putting existing power to pavement as it is.

For reference, I'm not against extracting more grunt...the prior 2 cars I owned had tunes...

As an observer, the smartest avenue seems to be to increase traction, not power.

If you get to the point that traction isn't the obstacle, go ahead and chase the extra ponies.

 

I just read an article about the auto makers wanting to enforce a digital copyright law passed back in 1998. It was not aimed at the auto world but due to the extensive use of computers in cars today they want to protect their software. They want to use the law to prevent 3rd parties from jail breaking and modifying their SW. This would prevent tuners from making changes in the ECU SW. Their claims is they spend time and money to develop their SW and it should be protected by copy write laws. It is still in discussion but if enacted it means only dealers can work on their autos. I don't have a need for any outside tuning but I am not in favor of preventing it. I can see not being able to play with safety systems but all else is fair game.

 

It wouldn't mean that only dealers could work on the cars (in any case, that would be against competition laws in Europe), since indys can still buy the software package. But it would hurt the tuners - who, these days, are effectively hackers.

The Digital Millennium Copyright Act was always designed to stop people 'messing' with software - any software, not just in computers but in any other electronic device, and even the protections built into electronic media like DVDs. I'm surprised the car manufacturers have taken this long to wake up to the implications; the music, film and game industries were all over it like a rash.

 

Traction and brakes are indeed the most rewarding and advantageous move any driver can make.

Michelin holds top honors, with the Bridgestone S-04s holding a close second. For pure grip and "damn the road noise", the Bridgestone RE-11 will eat both the Michelin and S-04s for lunch, but of course the 11s are in a totally different performance category altogether.
Of personal interest, is that Bridgestone has announced the release of a new tire, the RE-71r. I am told by my friend at Firestone that this new tire is a game changer, and will steal the honors from the RE-11 in shear grip, yet be more friendly when it come to road noise... (Bridgestone invited all managers to the track to compare the 11s v the 71s, and he says the new tire is nothing less than shocking...) This may well pull the Michelin out of the top slot very soon....
I might jump on a set when my S-04s die off... Just to see...

BOL

 

I'm annoyed - because I didn't plan ahead, I've had to put Pirellis on rather than Michelins. You have to order the Michelins about a month or two in advance, but I found myself with an MOT failure and no time to get the tyres I wanted before we go away this weekend. So, P-Zeros it is, then; at least I was able to get 305s.

 

The RE-71r's are suppose to wear out very quick, but are well priced.

 

As they have not been on the market but a very short time, I don't know of any reviews on wear. Have you found something?
I'm still a ways from replacing the S-04s, but will give the 71s serious consideration if they can control road noise.
Wear is the least of my concerns when I do battle with twisty canyon roads, but I do admit the Jag deserves a quiet cabin, which the RE-11s can not provide.
The S-04 is a great compromise, offering stunning grip, yet holding road noise to a respectable level.

Fingers crossed for the 71s....