I had a flat and the shop told me that because of the Quattro just changing two tires could ruin the driveline. It sounded like bull just to sell me four tires. Anyone no more on this

 

As long as they are the same size you're fine. They are just trying to make money.

 

didn't have any problems when I ran 2 new/old

i got the same spiel though @ American Tire

 

Owner's manual says all 4 tires need to have a diameter within 3/32 of an inch of one another. So if you have less than 10,000 miles on the "old" tires you are probably fine. Of course you can also just decide that you don't care what Audi says and take your chances.

 

I agree, 10,000 to 15,000 miles is the threshold. Any older than that and mix it with new tires, you are rolling the dice.

 

No drastic problems will result from uneven tire wear upon the 4. As long as they're all 35,40, 45 ect. Just put the new ones at the front since that's where you need most of your traction. Besides, everything in the Audi manual is exaggerated to get drivers to be paranoid and take their car in to the dealer to get raped

 

Try driving on SLIPPERY roads with non-same tires=> this is what the manual refers to, what an AUDI is for.

 

*stands up and claps* but they don't have to be ALL new, as long as they are TOO diff. in diameter, as stated before.

 

Put the new ones on the REAR. That way, in a panic braking situation, the rear will stop faster than the front.

Bob