Possible to re-calibrate the speedo for 255/35r20?

[allroadB8'r]

Hi!

I want to run 255/35/20 on my 2012 A4 B8 Avant, but the speedo will be off. Is there any way to program/calibrate so the speedo can be correct?

I know the 255/30 is the oem size, but I want to go with 35 if possible to get the speedo correct.

Thanks!

[MacFady]

No, as far as I know. Reason being that even at 200km/hr your speedo would still only be off by <10km/hr.

If you are running 255/35/19 right now and you go to 255/35/20 your speedometer will be 3.7% too slow. If on the other hand you go with 255/30/20 it will only be off by 0.02%, in the opposite direction (too fast).

Hopefully that helps, "I want to go with 35 if possible to get the speedo correct." is actually incorrect. Although you are keeping the aspect ratio the same, the rolling radius is not since it is now a 20" tire. The smaller aspect ratio keeps you almost identical to the rolling radius of the 19" wheel.

[allroadB8'r]

Hmm I got the information that it would be little bit more then 5% difference.. If it is nothing more then I will go ahead and purcahse the tires! Thanks for your reply