Wheels and Tires Post up threads with questions about wheels and tires for your Audi here
Sponsored by:
Sponsored by:

Tire size vs wheel size

Old 08-23-2009, 11:06 PM
Senior Member
Thread Starter
Join Date: Jul 2009
Posts: 208
Default Tire size vs wheel size

I found a beautiful matched set of 18" Audi wheels although from an A8 and I've got the same year A6 with OEM 18", Audi parts cross checked my VIN with the new wheel numbers and they'll fit but I forgot to ask if they'll take my OEM tire size..duh, mine are according to the book 245/40/18 tires whereas the A8 took 255/45/18? Will I need to order the 255/45/18 tires to fit these wheels and will this change things such as true speed readings or can I put my OEM sized tires on?
Old 08-23-2009, 11:18 PM
Jackmup's Avatar
2nd Gear
Join Date: Mar 2009
Location: New York
Posts: 1,227

Are you sure they'll fit in there? Do you have a 4.2L. My A8 has some wide tires on it I can't see them fitting my A6 at all. But my A6 is a 3.0 so I don't have wide wheel wells.
Old 08-24-2009, 02:13 PM
Senior Member
Thread Starter
Join Date: Jul 2009
Posts: 208

I'm sure only if the research the Audi people did cross checking my VIN with the new wheel serial numbers before I purchased them was correct and I made sure they knew the wheels came from a A8 which the wheel serials numbers showed, my A6 came with OEM 18" wheels with Adaptive Air suspension (A8 feature) so it's not the usual fare. The difference I found was the actual tire size between the two cars which seems fairly slight and your question will definitely need to be answered in my mind before I order tires, needless to say I am alittle more then concerned but still trusting the Audi research. I'd feel better if my OEM tire size will fit these wheels. BTW..I have the 3.2 engine.
Old 08-24-2009, 03:30 PM
Midniteoyl's Avatar
4th Gear
Join Date: Mar 2009
Location: Indiana
Posts: 3,042

Are you asking if you need A8 tire sizes? The answer would be 'no'. Use the one recomended for your A6 - 245/40/18, or any combination that keeps the diameter w/in 1% to be safe.
Old 08-24-2009, 04:13 PM
3rd Gear
Join Date: Sep 2004
Location: Newfields NH
Posts: 2,371

Put your std 245-40-18 tires on the wheels -Your car will not know the difference in wheels as long as the offset and wheel width is the same.
Old 08-25-2009, 02:36 PM
Senior Member
Thread Starter
Join Date: Jul 2009
Posts: 208

I was hoping I could stay with the same sized tire, thanks all
Old 09-02-2009, 09:41 AM
1st Gear
Join Date: Sep 2009
Posts: 63

the large stretched size of tire is best as it catches the road even when the car is moving at high speed.
Related Topics
Thread Starter
Last Post
Wheels and Tires
04-23-2011 10:12 AM
S Car Model Line
05-12-2009 02:41 PM
Audi A6
07-29-2007 11:52 PM
Audi A6
07-26-2007 05:24 PM
S Car Model Line
06-20-2007 04:38 PM

Thread Tools
Search this Thread
Quick Reply: Tire size vs wheel size

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.