Question for Brutal on XK8 Alignment....
 

Brutal,

Thanks for providing the 2003-and-newer S-Type owners a revised set of alignment specs to address the inner treadwear issue that some owners experience. I'll use your set of specs the next time I have to spring for an S-Type alignment....

Is there a similar set of revised alignment specs for the XK8? If so, can you provide it here, and can you specify to which model years it applies? Just installed a set of two new rear Yokohama YK580 all-season tires and while I believe my wife's XK8's alignment is good, the new tires may tell a different story after a couple of weeks and I want to be prepared....

As always, thanks for your willingness to share your knowledge and experience....

I know Brutal has responded a few times to some alignment threads I've created in the past. To my recollection, he hasn't mentioned anything similar to what the s-types experienced with alignment specification updates. I posted a few of my own before and after sheets from the jag dealer, and he didn't have any concerns. I remember him stating that if the camber is alittle out of spec to the negative side, that you shouldn't worry about it too much. I believe most of us try to stay right in that bottom end as close as possible, but w/o new springs, it eventually won't stay in spec.

What i've found is determining the optimum tire pressures to eliminate 'balooning' the center and wearing out the center faster...and the rear is more susceptible to that than the front. :)

On the topic of air pressure, what do you find works best? Do you run a staggered setup?

I'm running staggered 18"s and I found 32/32 seems to work well. The book calls for 32/35.

Matt,

Thanks for your feedback. I concur with your assessment that the rear tires may be more prone to center wear than the fronts are. When we took delivery of the car on February 3rd, the front Michelin Pilot Sport A/S Plus tires had 8/32 of remaining tread distributed evenly across the surface of both tires. I know they are a great all-season tire as all-seasons tires go. The rear summer-only Pirelli P-Zero Rosso tires had not quite 5/32 of remaining tread on both inside and outside edges and not quite 4/32 of remaining tread down both centers. My wife managed to get just under 5,000 miles out of the Pirellis before they were down to right at 2/32 of remaining center tread last weekend. They did a total of 22,600 miles before I made the decision to scrap them. I have no idea what pressures the original owner kept them. Our door jamb sticker calls for 32 psi up front and 34 psi in back. After a week of car ownership, I felt that 34 psi was a bit too much for the rears, so I backed them down to 32 psi. I've been running the car since then at 32 psi all the way around....

These new Yokohama YK580 tires are all-season, V-rated (yes!!), 60,000-mile treadwear warranty tires, so their characteristics are very different compared to the in-my-opinion very inferior Pirellis. They were mounted on Wednesday and had to be Hunter Road Force Balanced to get them right. I'm also starting them at 32 psi, so we'll see how this works out over the next couple of weeks. My wife already notices a better ride, and they certainly will not hydroplane in the rain as the Pirellis would have begun doing if I had kept them on the car much longer. I began researching these Yokohamas in mid-November, and I believe they are the best bang-for-the-buck for the characteristics that I care about - longevity, wet performance, relatively smooth ride, and relatively quiet. Time and miles will tell....

The front Michelins went from 8/32 of remaining tread when we took delivery of the car to 7/32 of remaining tread today after right at 5,000 miles of ownership. They have just over 16,000 total miles on them now. They carry a 45,000-mile treadwear warranty and while I do not believe they will quite get there, I will not be surprised if they manage to do between 35,000 and 40,000 miles....