TIRES - A6 4.2L - 255/40 R 17 v. 245/45 R 17

[cubart]

Hi, I have a 2000 Audi A6 4.2L (same as S6) and would like to put 245/45 R17 tire on. Because 255/40 R 17 are stock configuration, I am a little worried that the 245/45 R17 tire would be rubbing the fender lip, when turning the wheels to maximum. Any problems with this issue? thanks, Jure

[4Driver4]

Why on earth would you want to run the wrong size tires on the car? I'm sure the salesman's advice is in no way related to what he has in stock or is trying to move .

If it was my car, I'd run the 255's. No question.

[4Driver4]

Originally Posted by Miggsman

I'm glad to hear this is less likely with the 245/45 tires.

This is pure speculation. Do you really thing that .3 inch of sidewall is going to make the difference? Very unlikely.

[Boston Driver]

I am a bit late into this discussion, but did you also change the spare tire??? If not, and you get a flat, you are running a different diameter for a spare which can be trouble for Quattro. Also, keep in mind that the tire in that size does NOT fit very well in the spare well in the trunk. I ran 245-40-18 tires (with overall diameter of 25.7 inches) which is identical to the overall diameter of the 245-45-17 tires you just bought. I could barely get the spare into the trunk well (took a lot of "encouragement"), but it was almost impossible to get that spare out. I eventually had to deflate it, which defeats the purpose of a spare.

When those tires ran down, I replaed them with 255-35-18 tires, which match the overall diameter of the stock 255-40-17 tire at 25.0 inches.

Just my two cents...

[Just Me]

245/45 is by far my preferred choice:

1. 255/40 is not recommended for 8" wheels.
2. 245/45 has more sidewall and more load rating
3. is only 2.5% larger

Why on earth would you want to run a size that is wrong by the industry association and known to result in bent rims?

Grant

[4Driver4]

Originally Posted by Boston Driver

I replaced them with 255-35-18 tires, which match the overall diameter of the stock 255-40-17 tire at 25.0 inches.

But that's even *less* sidewall...and in Boston no less! You must get blowouts every day! Oh, the huge manatee!

LOL

[Just Me]

yes. In fact its not even debatable -- 0.3 is 0.3. Its not zero. Bigger.You may ask how significant it will be, but that's a different question.

The load rating is (in most cases) two points higher, which is also significant.

We have to work within limits. In this case 0.3/4.0" (OEM sidewall height) is 7.5%

As i noted (many months ago in this same thread) if you really want to protect rims - do what i did - go to 245/50-16. But then you give up some handling. So i may go back to 17 (fat fives forged), but i will go back to 245/45-17 because its the best i can do.

G

[Boston Driver]

Nope. Only time I've ever had a blowout was from a screw in the road. Sidewall would not have saved me.

[GTA_Driver]

Originally Posted by Just Me

Why on earth would you want to run a size that is wrong by the industry association and known to result in bent rims?

Grant

Damn, if only Audi consulted the industry association! They are just so new at this, they don't know what they're doing.

I have never bent my 17".

What you get out of the 0.3 " taller sidewall is negligible. FYI, my 19" 30-profile tires 265 wide on 8.5" rim were SOFTER than my 255/40-R17 tires. The rubber makes MORE of a difference than going from 40 profile to 45.

[Just Me]

I 'm not sure that sidewall blowouts are the appropriate measure. I've never ever had a blowout. On the other hand, i have bent - mostly mildly - 11 rims. Mostly inside ( unsupported) edge; flatspot. But it makes these cars (and B5s) vibrate. That's what i want to protect against.

G