I just got out of a pretty loud debate with a friend. He's terrified putting on his spare wheel (which is a Michelin) on when the other 3 are Pirelli's on his 03 RS6. All in same size and dimension. He claims the quattro is going to break, I say he's over-reacting. I know you're supposed to have somewhat similar sizes on, but then again I've never ever heard of a broken down Q.

My question is - has anybody ever heard of a quattro breaking down? EVER? For any reason??

 

Your friend is over-reacting. As long as the rolling diameter is the same, it should be good.

I have never heard of a quattro system breaking down. They're very well built.

 

I have heard of differentials break down due to too much power that's about it. It did not have anything to do with the wheels/tires. Your friend should be fine.

 

lets assume that a quattro car has 20k miles on it. the spare tire is in good condition and has never been used.

If you put that spare tire on and drive for porlonged distances and for a long time (ie: no intent to fix the flat and drive forever on the spare) you will start setting all kinds of faults for ABS and traction control. You may get all kinds of faults/warnings but mechanically the car will for fine for a long time.

After a LONG period of time you will wear on the rear diff if its on the rear, or the trans if its a front tire. This would only happen after a lot of driving, and ive only heard of this happening once.

If it were my RS6 id just replace all 4 and be done with it. Depending on what happened to make the flat tire id try to get it fixed.

 

Jox,

Tell your friend not to worry, he can use that tire for a short time though.
Reason I say is only because it is unsafe to have 2 different tread designs on the same axle and for nothing more. As far as the quattro getting damaged it wont due to driving with 3 Pirelli's and 1 Michelin. He wont get any codes or faults due to that.
Bottom line is you should have all 4 tires the same but until a fix is ready he can drive like that. The quattro system is pretty indestructable, I havent heard of any breaking down, ever.
The tire he has for spare and if the Pirelli's are the same size and type of tire wont do any harm to the car.

Bajo

 

Thanks for your replies guys. Just as I thought, so I'll forward this thread to him.

He (well, actually his wife.. ) scraped his rim the other day and was going to use the Michelin while it's being repaired.

 

I just have an idea...what would happen to the RS4 just turning off the front differential...how would a RS4 RWD work?? that should be awesome IMO