Who is running 265/35/20 tires? Any issues?
#3
#4
#5
Well to be fair I am a decade out of date, but the RNS-D for instance wants to know tire size for the "inertial" navigation - e.g. in a tunnel, other lost GPS lock times. It's not inertial of course, but it counts pulses from the wheel sensors to know how far you'd travelled. Running "wrong" sized tires would lead to some occasional oddities when approaching intersections (like "turn right ahead" when you were halfway through the intersection), noticeably longer "re-lock" times when returning to coverage areas, and less reliable startup directions. Admittedly one had to know what one was looking at to separate these from random GPS issues, but those of us who were doing the first US RNS-D installs were looking really closely at what was going on
I'm just now coming up to speed on MMI Touch, so I honestly have no idea if it matters to the C7 cars - but I do note Audi picked a pretty oddball 19" tire size (255/40-19) to match up to the 255/35-20 size they used on the 20" wheels. I tend to believe they did that to avoid more than just the slight speedo inaccuracy alone.
YMMV and all that, but my personal advice would be to stick with the stock size. As noted in my UHP A/S tire thread, I ordered 20" wheels on my car solely to keep a more common tire size, so FWIW I'm putting my money where my mouth is on this one
I'm just now coming up to speed on MMI Touch, so I honestly have no idea if it matters to the C7 cars - but I do note Audi picked a pretty oddball 19" tire size (255/40-19) to match up to the 255/35-20 size they used on the 20" wheels. I tend to believe they did that to avoid more than just the slight speedo inaccuracy alone.
YMMV and all that, but my personal advice would be to stick with the stock size. As noted in my UHP A/S tire thread, I ordered 20" wheels on my car solely to keep a more common tire size, so FWIW I'm putting my money where my mouth is on this one
#6
AudiWorld Super User
Thread Starter
Well to be fair I am a decade out of date, but the RNS-D for instance wants to know tire size for the "inertial" navigation - e.g. in a tunnel, other lost GPS lock times. It's not inertial of course, but it counts pulses from the wheel sensors to know how far you'd travelled. Running "wrong" sized tires would lead to some occasional oddities when approaching intersections (like "turn right ahead" when you were halfway through the intersection), noticeably longer "re-lock" times when returning to coverage areas, and less reliable startup directions. Admittedly one had to know what one was looking at to separate these from random GPS issues, but those of us who were doing the first US RNS-D installs were looking really closely at what was going on
I'm just now coming up to speed on MMI Touch, so I honestly have no idea if it matters to the C7 cars - but I do note Audi picked a pretty oddball 19" tire size (255/40-19) to match up to the 255/35-20 size they used on the 20" wheels. I tend to believe they did that to avoid more than just the slight speedo inaccuracy alone.
YMMV and all that, but my personal advice would be to stick with the stock size. As noted in my UHP A/S tire thread, I ordered 20" wheels on my car solely to keep a more common tire size, so FWIW I'm putting my money where my mouth is on this one
I'm just now coming up to speed on MMI Touch, so I honestly have no idea if it matters to the C7 cars - but I do note Audi picked a pretty oddball 19" tire size (255/40-19) to match up to the 255/35-20 size they used on the 20" wheels. I tend to believe they did that to avoid more than just the slight speedo inaccuracy alone.
YMMV and all that, but my personal advice would be to stick with the stock size. As noted in my UHP A/S tire thread, I ordered 20" wheels on my car solely to keep a more common tire size, so FWIW I'm putting my money where my mouth is on this one
Last edited by Vijay; 01-01-2014 at 07:31 AM.
#7
A 265/35/20 tire will only add 7mm overall diameter to the wheel/tire combo. Your tire diameter can change this much over time with treadwear alone. You really have to go with over 3% before you start to really notice any functional difference. A 7mm difference on a new tire is a 1% change. I am not worried one bit about the functionality, just the fit. FWIW, I ran 275/30/19 on my RS4 which was a 2% change (13.5mm smaller diameter) and I had no issue. Likewise from my expereince with my M3 and the info on the M3 forums. No issue whatsoever with small variations in tire diameter sizing in terms of function.
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#8
A 265/35/20 tire will only add 7mm overall diameter to the wheel/tire combo. Your tire diameter can change this much over time with treadwear alone. You really have to go with over 3% before you start to really notice any functional difference. A 7mm difference on a new tire is a 1% change. I am not worried one bit about the functionality, just the fit.
I confess to being mildly curious as to why you'd want to go ~4% wider on the tire though.
#9
AudiWorld Super User
I'm running 265/35 on a 20x9 ET25 rim, which pushes the wheel 26mm outwards compared to stock. In roughly 13K miles I've rubbed twice and it was in the same turn on a big bump on the outside front wheel while the suspension was loaded. If your offset is less aggressive then you should have zero issues with rubbing.
For reference, this is with a Michelin Pilot Super Sport.
For reference, this is with a Michelin Pilot Super Sport.
#10
AudiWorld Super User
Thread Starter
You lose nothing and more grip is more grip. For a car the size of the S6, I think a 255 is a little undersized. The S7 does, in fact, does use a 265/35/20. Not sure why they went with 255 on the S6. In fact, So far as I remember, the C6 S6 used a 265 tire as well. It also adds just a little more of an air cushion.
Last edited by Vijay; 01-01-2014 at 01:23 PM.