This is not about the uneven tire wear due to excessive camber...I fixed that by changing the shims on the half shafts and now within spec.

However the set of Michelin Pilot Sport A/S 3 tires I have on currently are at the wear bars with just over 17k miles on them! No, the boot is not full of weight, not doing any aggressive driving or even long distance. Most trips are between 2-20 miles for local errands or 100 miles for going to Tucson and back. I maintain the pressure at 32-34 psi.
Was expecting to get into the 35k mile range on these tires, not 20k miles.

Anyone else having low mileage experiences on the rear tires?

 

Check the underside of the armrest for the Jaguar recommended pressure for your wheel size and expected max speed. It is much lower than what you are listing.

 

The Vehicle Care Guide that came with my ‘02 XKR lists “normal” pressure as 32 front and 34 rear for my stock 18” wheels. It also lists an alternative pressure for maximum comfort with speeds limited to 100 mph as 26 front and 28 rear.

I also have found that using the “normal” pressures listed result in accelerated wear in the center of the tread, which is the classic indication for overinflated tires. I’m on my 3rd brand of tires, and all three brands show the same wear characteristics.

To keep the tire wear even I’ve had to lower the pressure closer to the “comfort” recommendation.

 

After nearly a year of experimenting with tire pressures after we acquired my wife's 2006 XK8 in early 2012, I found that the rear tires' treadlife is maximized at 28 to 29 psi. Been running them yearround at that pressure since late 2012. The rear tires typically reach the 33,000 to 34,000-mile mark before they need to be replaced....

I run the front tires at 32 to 33 psi yearround. They typically reach the 45,000-mile mark....

I have stayed with Yokohama YK580 tires from Discount Tire since discovering them in late 2012. I believe they are no longer available....

 

as tire compounds are continuously evolving, I wonder what Jaguar’s recommended tire pressure’s would be today ?

Surely there are more than a few owners who have faced these same challenges ?


Z

 

There was much more forum discussion regarding optimum XK8 / XKR tire pressures 5 or 6 years ago. Yes, tire compounds have evolved during the past decade but I believe the primary issue remains the fact that most new owners continue to overinflate their rear tires regardless of brand or size before realizing they need to back those pressures down in order to extend their treadlife....

 

By the way, the three brands of tires that I’ve tried are, in consecutive order,
BFG G Force COMP 2 A/S

Pirelli P-Zero A/S

and Michelin Pilot Sport 4 All Season


I haven’t had the Michelin’s long enough to tell
much. But I am checking the tread every hundred miles with a tread gauge. Should be able to find out if using the lower tire pressure recommended (under 100 mph / maximum comfort) is going to keep the tires from wearing prematurely in the center of the tread due to over inflation.

 

My XK8 has the optional 19" wheels/tires.
And I have taken the advice and dropped the pressure in both front and rear; have fronts at 32, rears are at 30. Of course too late for the current rear tires; looking at the Bridgestone Turanza high mileage Grand Touring tire...has good reviews anyways.
Thanks for the advice.

 

one thing worth noting is that when one changes from a factory specified tire that it is necessary to compare the load rating. When one replaces a tire with another type of the same size but with a higher load rating it is necessary to increase the air pressure above specification to achieve the same load capacity. The Pilot Sports on my car in the front have a higher load rating than the factory specified tires, thus 32 PSI is somewhat more than the comfort setting. The vehicle also tramlines more at lower pressures that are still within the proper ranges. My car has the 18 inch staggered setup which supposedly has the problems with rear tire center wear.

I have been running the cold inflation pressure of the rear tires at 32. Measuring the tread for the past four years there appears to be no excessive wear in the center tread.

When i try lower pressures the car does feel softer, but washboard surfaces seem a little more bouncy and performance a little flat. Don't like it.

Be forewarned, the predictor of catastrophic tire failure is low pressure as heat is the enemy. Running the rears that low might be cooking the tire and doing long term damage, especially if the load range is higher for the new stock over original spec.

My theory concerning the center tread wear is that it might not be pressure as much as centrifugal force and tire design. Thus, could be a brand specific matter.

I have a perfect set of extra front wheels and have toyed with matching the rear to the front upon replacement, potential problem gone. However, i have grown a little fond of the look which i never thought that i would like. FYI, it is not about traction as it is grip to prevent lateral forces and oversteer. A designer for another brand also told me that when low profile tires became common, the rear mounts created a visual perception that they were too small. It was not a drag car style thing or like an American Hot Wheels toy look but overcoming a sense of imbalance. The same size tire on the rear as the front looks smaller. I switched the tires around on one side to try to see it and invited a few others to look and they "saw" the imbalance too.

Even if they wear out more often, i am using firstly, safe pressures and next what feels best to me. The car is a frugal person's dream for a GT in a lot of ways to have a toy with such low acquisition and servicing costs. So, if there is a minor loss in the mix, so be it. One only lives once.

 

weren't you already at 32 psi in front ?

regarding the wear on your tires:

was the center of the tread worn more ?

were your front tires worn the same as the rears ?


Z

 

fwiw, the load range on my current tires, Michelin Pilot Sport A/S 4’s, is the same as the original equipment tire; Pirelli P-Zero. Both have load range of “XL” with maximum load of 1,764 lbs. And both have the same service description also : 107Y

shouldn’t then the factory recommended air pressure for the OE Pirelli’s also be the same for the Michelin’s ??

Z

 

Hi Zray,

The Pilot Sport tires on my car are the A/S 3+ 100Y Front, 99Y Rear
When i looked up the original front tires, Pirelli P-Zero at that time, the Front was less (i recall 97) and the rear the same as the Pilot Sport is now.
I run 32 cold front and rear with even wear across the treads. Also, i run a TPMS and notice that at lower pressures the tires get warmer and pressure increases by a greater degree when driving.

 

The fronts were at 33 this morning when I checked them, so I lowered them to 32.
The rear tire wear was pretty even across the width, with a bit more in the center by eye-ball, not measurement.
I no longer replace tires as a set; the front ones were worn-out due to an alignment issue, had to be immediately replaced, the rears at that time were still good.
It was later on that the rears wore-out and were replaced.
I am not running matched tires on all four, just matched on the axle; get to try-out different tires this way.

 

Hmmm.... lots to think about above, and I haven't put on the mileage that others have had in the Jag. But I've alot of experience of tyre wear in BMWs, Porsches and now the Jag in the super hot temperatures of the Middle East.

Basically during summer I run the tyres in the lowest pressure range permissible during the 50degC+/120degF+ summer temperature and then, during the cooler winters, I pump them up . Over the decades I've tried Dunlops S/Sports, Michelins Pilots, Bridgestones and Pirellis P-zeros. Tyre wear tended to vary according to temperatures, driving style and the wheel camber and I've previously played with the tolerances of wheel alignments to try and get as much tyre life as possible. I was careful so if I was planning a track day I would re-instate the factory alignments.

11,000miles was the worst I got from the Porsche 911 with Pirellis P-zeros, 20,000km the best with Bridgestones with the BMW M3. I guess we're all mainly summer drivers, gunning the engine whenever we can, so we'll never get the tyre manufacturers' stated life expectancy. Still I welcome the opportunities to lay down "eleven-sy" skid marks & hairballing around a bend, rather than be a careful Sunday driver watching my tyres & brakes. There are more important things in life to worry about.

 

Given that the XK’s are a GT car that’s driven with some spirit and enthusiasm from time to time, or continuously, as the case may be, what do the old timers on the forum say should be an expected tire life when the tire pressure is dialed in correctly ???

on my new set of Michelin set of Pilot Sport All Season 4’s should I be looking at replacement at 20,000 miles, or is 15,000 more realistic ?

I don’t turn off the traction control with the intention of laying down a single stripe of rubber, or other such wasteful pastimes. But I do enjoy long trips at responsible highway speeds, ie under triple digit mph.


Z

 

TPMS sounds interesting. How did you add?

 

Not whitehat, but I’m using one similar to this:

Tire Pressure Monitoring Systems TPMS 6 Alarm Modes Wireless Solar Power and USB Charge with 4 External Sensors Real Time Pressure and Temperature Alarm Auto Safety Monitor for Rv Trailer Car Truck

Z

 

I was able to get about 50K out of my first set of A/S 3 tires. The rears did wear out a bit before the fronts were due but the rear wear was not abnormal on edges or centers.
I was keeping them at 30-32 front and 26-28 rear. Also nitrogen filled.

The second set (A/S 3+) was on the XK8 when I sold it. They were also wearing very well so far using those pressures and already had about 25K on them with lots of tread left.

Those A/S 3 tires are the best I have ever mounted. Quiet and smooth right up till I replaced them.