A84.2

I am thinking about purchasing 275/40-20 for my A8 instead of 265/40-20. I drive roughly 35K miles a year and the break in cost wouldn't hurt. Will this negativity affect my vehicle? Will it cause long term damage? Please help, thx!

KnappAttack

I've been running GoodYear Sport All-Season 275/40-20 since just after I purchased my A8. No problems, No negative effects at all. Vehicle actually looks better with the slightly wider skins on. I'll buy them again for sure. 15,000 miles and none the worse for wear. Looking like they will go over 50,000 miles but still to early to know for sure. Average tire mileage for me with Quattro A6's for over 300,000 miles is only about 25,000-30,000 from a set of tires. This A8 and the GoodYears will for sure far exceed that, and the all season traction including the dry, wet, snow traction, quiet smooth ride and I couldn't be happier!!!

A84.2

Ok thanks. The larger tire has not interrupted sensory function? I'm hearing a larger tire can interrupting adaptive cruise etc.

KnappAttack

Does not effect my adaptive cruise at all, nor should it. The difference in Dia is not even measurable when putting the a ContiSportContact3 265/40/20 side by side with the GoodYear 275/40/20. I was hoping for a slight bit taller tire, but it's so close you can not tell it at all. They are wider for sure and you can easily tell that however.

A84.2

Ok so now I'm hearing the larger tire may hurt the transmission because the car will have a false sense of speed. What are your thoughts? Thanks again. Your responses have been helpful.
Seems like we have similar 8s. I have a 2011 racing package dark grey.

KnappAttack

Won't hurt the transmission one bit. Someone has no clue what they are talking about with you whatsoever. There is more diameter difference from tire wear than there is from going to a 265 to a 275 tire. According to Tire Rack there should be a .3" Dia. difference between my two sets of tires, but it's not there when I put them side by side.

IMO You could change Dia. by 3" or more and not see a problem (physical fitment aside). You will essentially gear the car up and spedo will read slower than actual speed is all. No reason if you change all four tires that it will effect any sensors or create any problems. Now if you only changed two tires, front or back or side to side you would have a problem! As long as all four are the same size you will not have a problem. You can go bigger or smaller it will not mater. Smaller will gear the vehicle down and larger will gear it up, but it takes a big step in size to have much of an effect.

A 8

Agreed, I think the comments about hurting transmission etc is based on having different size front vs back which would perhaps stress the front to rear clutch or gearing.

Over in Europe its more complicated than just the size, I am just about to change mine and trying to get the Conti silent did not work so I am back to the GoodYear F1, these are available in 265/40/20 with or without AO spec which stands for Audi Original. So if I want to stick to a AO spec'd tire I can only choose 265/40/20 and 3 tires, GoodYear F1 Assy and Continental SC3 and Pirelli PZero.

I've tried to get info on what is different between the AO spec and not but its proven difficult so far.

Don't you guys have AO spec'd tires in the US?

KnappAttack

Yes, we have OE spec tires here, but there are better choices out there that last longer, are quieter or may do all sorts of things better.

I don't feel the need to obsess about sticking with an OEM tire at all.

A84.2

This is great. Any recommendations for where to purchase? Online or local tire dealer? The difference in cost is significant but you lose service when purchase online.

KnappAttack

I get my tires from Tire Rack and my Audi dealer installs and road force balances them no problem for less than $100. I'd only trust them to mount and balance them. Audis are horible when it comes to anything less than a perfect road force balance.

Tried a Tires Plus once and they claimed to do a road force balance, it shook bad, took it back and they road forced again, still shook, took it to my Audi dealer for a balance and they got it perfect. Lesson learned!