RED HORSE

Had a new set of Michelins (265/35 21) installed by the dealer yesterday. Took a 250 drive today and they are great. I'd also like to point out, based on posts from some, that these tires came from Tirerack. I know they came from Tirerack because I went out to the warehouse and picked them up. They were $355 each. The best the dealer could do price wise was $425 each. The dealer said they had no problem if I brought the tires in with me, installation cost would be exactly the same.

I like the ride and handling so far much better than the Conti Sport Contacts which came on the car ('15 S8).

andrewmr

It's nice to know that the Michelin's perform/feel better than the Conti's.

How many miles did you have on the originals?

Why did you go with 265's versus 275's? EDIT: I guess it could be because they don't come in 275's....

Ferrari27

Bummer. I wanted to switch to the Michelins last month for my '13 S8. The service manager and chief mechanic at the dealership went sky high when I said I wanted to go to the 265 Michelins. Now I have the Contis....again.

RED HORSE

Mine came with 265's. The Contis only made 20,000. But I had 4 flats also during that period plus all the rear suspension had to be removed and replaced to install a new fuel tank.

dougpaper

so my came with conti's 275 35 21, stock, will the 265 35 21's work with the speedo being accurate? Not many choices in the 275 range and nothing in all weather and I live in pa. so this winter will be interesting

MP4.2+6.0

You can test your car with any of the free GPS speed apps. I have a couple on my iPhone. With only 3300 miles on car, I tested my 275/35 21 OE Dunlops with an app. I found a typical 1, sometimes 2 MPH optimistic error at interstate speeds. Relatively modest error compared to some others. The feds big time fine manufacturers for speedos found to understate actual MPH. So the incentives (penalties) are basically there to cause manufacturers to let them read a little optimistic, especially relative to even small possibilities they will read too low.

Test yours and you will know your baseline. Net, using 265/35 21 compared to 275's will make any error worse, not better. But it won't be huge.

In my case, I found the S8 ride with the 21's a little unsorted. Plus the OE wheels in 21's are all pig heavy and I think the pretty overboard unsprung weight had something to do with it too. Switched to the lightest OE D4 appropriate 20 forged and removed about 9 pounds per corner (wheel and tire assembly). That aside, went with 275/40-20 for tires. Thought about 265's, but in 20's there are some 275 choices I liked better, both summer and A/S. Beside the ride matter, the static tire diameter of a 275/40-20 is about .2 inches greater than the 275/35-21's. It was just the right amount to basically eliminate any speedo error when I retested via same GPS app.

RED HORSE

Both GPS devices I have show my '15 S8 with the 165's the indicated vehicle speed exactly matches the GPS speeds.