joedirt1

I bought my 2005 A6, 4.2 several months ago. I noticed the tires are not the same kinds. The front two are the same and the rear two are the same. Is this OK? They are the same size and speed rating; the tread pattern is close to matching but not identicle.

I had a Grand Cherokee full time four and that transfer case is very sensitive to different tires. That had to have the four tires the same.

KevinGary

Quattro is also very sensitive, maybe even more. I would have the same tires all the way around, with approx. the same tread life as well.

pavils

Yep, exactly like KevinGary said - same tires, w/same tread-life are highly recommended; tires, while expensive, are cheaper than most other parts of the drivetrain

It's enough to make you think hard when the tire places pitch the extended/hazard insurance packages when you purchase a new set of tires, given the ramifications (costs) should you lose one...

DirtyVegasTT

With similar sizes and wear you should be fine. The system is not as sensitive as we are consistently led to believe. The reason? Well, Audi techs and sales people run staggered setups... when I asked them about the tranny issue on our cars they said that it has a certain tolerance for these type of things.

If anyone is that adamant about this not being the case, then tell us how many tranny issues have there been related to offset or uneven tires? And yes, there are plenty of people running offset tires on Quattros.

davekr

along with "tires that match" are pressures suggested to be run equally?

tturner2b

id also be interested in hearing more about this. Particularly anyone who has seen some hard data on actual xfer case problems from tires or some analysis on acceptable tolerance.

pavils

Totally agree with you: the system HAS to have decent tolerances built in, as our shared experiences would suggest - no bonus points awarded to the design engineers if the system is so fragile it (metaphorically) falls apart as soon as some reasonably expected event occurs, say one of the tires is (significantly) lower in pressure than the others, one is wearing a lot faster than the others (alignment issues) or even all 4 corners aren't exact duplicates (rolling weights, tires, etc)...

As to the question of exactly what the tolerances are, what configurations are worst/most likely to lead to failure, how long (miles) the car has to be in a configuration to get to a failure point - whew, I'm sure that data is available, but I would also hazard it's likely also Audi-internal and probably extremely confidential

Sorry if my comments made it seem I was being adamant/"intolerant" on this - not my intent.

To the OP: if I was in your situation, and the rating & wear on the two pairs were roughly equivalent, I would keep things as-is until it's time for new tires, at which point I personally would go for a new (matching) set of 4.

my $0.02....

scooter80

As long as the circumference (rev's per mile) of the tires is near the same, it will be more than fine. Get matching when you are in need of new tires. For now, worry not!