NABS4

My car came with 255/40/19s and I'm trying to decide to go with either 225/55/17 or 235/55/17.

The "standard" size for the car is 245/45/18, so 225/55/17 (+0.24%) is closer to that size than 235/55 (+1.83%).

However, if Audi did in fact calibrate the car to 255/40/19s, 235/55/17 (+0.54) is close to the stock size than 225/55/17 (-1.06%).

I don't think either is a wrong choice. At the moment I'm tempted to go with 225s. They've got a slightly higher load limit (101) than the 235s (99), but that's about it as far as differences.

Thoughts?

mwar99

Will the 17's fit over the front caliper?

NABS4

Sure will. Had them on the Q5, which has bigger front brakes than the A6.

Anyone?

TheNit

I have a 2013 2.0T. I put 225/55 R17 (Hakka R2's) winter tires on my car and there's no problem.

NABS4

Yes, there would be no problem with either 235/55 or 225/55. Both are fine, but given the scenario i outline in the original post, which gives better speedometer accuracy?

TheNit

Either one isn't that far off. Using the 19's as "stock", when the speedometer reads 60 mph, the 225/55/17 would be actually traveling at 59.4 and the 235/55/17 would be 60.3. I guess it would be better (radar et al) to be going slower than what you think. But then again, I believe all Audis (and VWs) already show a higher speed on the speedo than your actual speed. I have a Passat and an A6 and whenever I pass a radar display (you're going too fast...), the speedo is reading 1 or 2 mph more than what the sign shows.

I've always thought the goal with snow tires was to get the narrowest tire (to cut through the snow) with the highest sidewall (to protect against pothole damage).

This would suggest to me that the 225/55/17 would be more appropriate.

I used the Miata.net tire size calculator (Tire size calculator).

Grapeking

Second this line of thinking.

Jim1969

Should you go minus one or minus two for winter tires?

das2.7t

Depends what you are trying to accomplish. My Micheline Pilot Sport PS/2 summers are 255/40-19 and Bridestone Blizzak WS70's are 225/55-18. If you are running 20's, the step down to 18's are just fine. If you are running 19's, the step down to 17 would be fine as well although may seem small in the wheel well. The 55 sidewalls on my Blizzaks give plenty of extra sidewall height with no perceptible difference in speedo readings.

Most conversion tables would say I should be running 225/50-18's but that is a touch smaller than stock. My 225/55-18's are just a touch taller so it gives me a hair more clearance in the snow since I am running the stock sport suspension.