richard_A5

I have bought an A5 (2014) with 245/40 R20 mounted, and worry that the wheels might be to big and interfere with wheel housing.
Anybody knows if this is a real concern ?
I am not keen on getting 245/30's (comfort-related9 so would have to buy new rims if it is not ok to use these.
BR
Richard

Glisse

That is a bizarre fitting - 245/40 is the OEM tyre spec for an 18" wheel. Sidewall profile ratios are a percentage of the tyre width, so it isn't hard to work out the difference in "big". The correct width of a 20" tyre on a 2014 A5 is 265mm, with a 30 profile, but the wheels should be 9" width, and who knows what you have.

Really better for you to look at the OEM specs for a 2014 B8 A5 here:
https://www.wheel-size.com/size/audi/a5/2014/
And then plug all the numbers into the calculator on the same site, here:
https://www.wheel-size.com/calc/

But yes, you should have a concern running two inches higher than OEM spec, as it is likely to compromise ABS performance, your speedo will be understating speed by about 8% so expect speeding tickets, and the odometer will be understating mileage by the same amount. There is a fair amount of room under the fenders of an A5, so I think whether the tyre hits anything in there under compression (AKA a bump) is the least of the concerns.

A 245/30 R20 would go too far the other way (but only by a small amount), yet would be truly horrible to drive on with a B8 A5 regardless of what suspension option you have fitted to your car. I think your best options would be to replace the tyres with 265/30 R20 to get the geometry back to around where it should be. And whilst the ride will be better than if you had tried to use 245/30 R20, it will still be pretty harsh. Or get new wheels. 19" wheels (with 255/35 R19 tyres) are about as far as you want to go on a B8 if you have even the slightest concern over comfort. If that concern is more than slight, get 18" wheels. I found the B8 chassis and suspension is quite sensitive to wheel size, more so than the new B9 model (which has a stiffer chassis, so can run softer suspension settings).

Good luck.

Doc@tirerack

Agreed, 245/40R20 is way too tall........255/30R20 or 265/30R20 are sizes we use. If comfort is a concern, sell the 20" and buy some nice 18"

richard_A5

Thanks for prompt responses !

It does seem i need to get a new set of wheels, as i have concerns over comfort with lower sidewalls.

Again, thanks a lot

best regds
Richard