allroad'Ed now

according to the folks at Michelin customer Service, it effects Audis the same way:

Discount Tire has a great system for keeping up to date on all manufacturer bulletins. Just takes a good sales person to read, remember, and tell customers. I have such a person at my local store.

The bulletin from Michelin states that :
<b>Michelin Pilot Sport A/S is not an approved tire for new Mercedes cars</b>

I will try to get my paws on an actual copy of the bulletin, but it effectively says that the tire is causing "tracking" problems when put on newer MB E-Class, C-Class cars. As such it has caused many owners to go back to the MB dealer to complain that there's something wrong with the car. MB will no longer authorize this tire's use on MB's.

Per my conversation with a Michelin engineer, the "tracking" problem shows up as the rear of the car kicking to the side on bumps. This is exactly what I've been experiencing with all 3 sets of Sport A/S on both my A6 and the allroad. And exactly why Michelin offered to give me any other set of Michelin or BFG tires in exchange.

What a shame. These tires are fantastic in every other way and I've been one of the foremost advocates of this tire since I put on my first set more than 2 years ago.

TheLex

specifically, if the tire is really a high performance tire and sticky, could it react to laterall forces more rapidly? That's just a wild guess.

OTOH, I know from personal experience that MBZ's have lousy tracking at times. Both my dad's MBZ's and my 300CE and SL500 would pull to the left constantly whenever I was in the left lane. I realize that the road is crowned, and the dealers would always mention this, but hey, the allroad doesn't do this. I'd have to actually turn the steering wheel from 12 o'clock to about 2 o'clock just to keep the car going straight. I never felt this was normal, but the dealers refused to admit that there was anything wrong with the cars.

Ex-PzKW Cdr

Mine are fine, no tracking problems on 2 different allroads.

moto-one

in the shock, in combo with hard sidwall tire, will cause it and it's likely the cause in the ar's doing the side dance over sharp bumps. That's why you didn't have the same reaction with your snow tires or stock 17s. On my Plastic car I have JRZ quad adjust shocks, going from my street tires to my race tires (both Michelins) I have to reduce the hi-speed damp/comp by 2 clicks. The tire is part of the dampening system.

allroad'Ed now

they didn't jump or kick to the right on bumps. And heaven knows those things had stiff sidewalls. Think I could have run them at 5psi and they would still look fine. The SP5000's on my A6 were horrible at following every groove in the road... just darted all over the place but no problem over bumps. Switched them off for my first set of Sport A/S and although the dartiness and sensitivity to road crowns went away, I immediately got a kick to the right from the rear. Back then I just thought it was from 70,000 mile old shocks.

Don't get me wrong. I love the Sport A/S in every other way, just not the rear kicking to the right on bumps and frost heaves.

And what you say about the plastic car, I know the feeling, just in a rear engined 6 cylinder toy. Big sway bars and torsion bars, combined with stiff sticky track tires in no fun on the street. I too back off the shock settings and even the sway bars for the street.

ColoQuattro

Very interesting. I have been experiencing a steering wheel ossillation at 52 MPH with my 245-45-18 Pilot A/S. Have tried switching fronts to back and there is no difference, same ossillation. Put the P-6's back on and there is no ossillation. The only thing that I have yet to do is check allignment but the car only has 8000 miles so I seriously doubt that allign is off.
I have been working with Discount Tire who has actually been very accomodating. Now they are offering to put me into another tire of my choice. They say that the tire is not a good match for the AR.