A4 B6 Quattro Avant wheel/tyre upgrade


Registered User

Does anyone know if a 18" Rim and tyre fit in the spare wheel well of the avant? Looking to upgrade from 16" Rims when the better weather comes.
Being a Quattro I gather that all the wheels must be the same size so I cant use the 16" Spare in the event of a puncture...is this correct?


Staff member
You can use any size wheel and tyre you like BUT the rolling circumference of the tyre must be the same, I have 18" 235/40 tyres, but the rolling circumference is the same as my 215/55/16 which is the spare.

So by that logic the 18" wheels would fit in, but I have never tried one.

Use a Tyre Calculator to find out tyre circumferences.


Registered User
Once I've washed them and taken pics, I'll be putting my five 18" original 2003 S4 alloys up for sale.

I'm not sure of what offset etc you need but it maybe something to consider.

p.s. I'll also be selling my 18" RS6 replicas but theres only four of them.


"Stick a V8 in it!"
Staff member
VCDS Map User
I dont see any point in trying to get a full size spare tbh, i generally consider my spare as a temporary wheel only, even though its a full size 16" alloy, i would never be leaving it on the car for anything more than enough time to get the wheel its replacing fixed.

Craigs B5 S4 has a full size 17" spare which fits in the wheel well just fine. I think the problem you may have is the width of the rim. As people have said the diameter is the same, but the larger alloys are generally wider (say 8x18 rather than 7x16) and this might mean it either wont fit at all, or will stick up into the carpet.

As long as the circumference of the tyre matches the wheels on the car, you wont have any issues with quattro.


Registered User
My oem 17" Sport alloy fits ok in the spare well but because its considerably wider it does prevent the plastic cover from seating correctly but only ever so slightly.


Registered User
Surely my S4 wheel well isn't any different to the other B6's ??

If I can get in a wide 18" wheel/tyre then I don't get why the smaller/narrower ones wouldn't fit.


Registered User
I don't see why a 235/40R18 wheel wouldn't fit into the spare wheel well.

My car came with a space saver. A mate gave me a 18" RS4 rep' and I'm going to fit one of my old tyres to it and use it as a spare.

I very much doubt the space saver will fit over the S4 front brakes, and I don't want to find out the hard way!!