DHS

Friends, I have a CPO '16 S5 incoming. It replaces my beloved '09 S5 that I have written about in other threads. It died in a crash with a deer.
The '09 had a dedicated set of 18" wheels for snow tires. They were take-offs from an A5, and fit perfectly. I have always done -1 sizing for snows.
I still have those 18" wheels and wonder if I will be able to use them on my new S5. I checked and the bolt pattern, 5x112 is the same. So that is a good start. The A5 wheel, as far as I can tell is 8.5Jx18 ET29, Again, it fit fine on the '09 S5 which has 19" stock wheels whose specs are 9Jx19 ET35. Never noticed any troubling offset issue or brake clearance issues. The 19" black optics wheel on the '16 is 19x9 with 33 offset, so 2mm less than the older S5 stock wheel vs. ET 29 on the A5 wheels. So I am dealing with a 4mm differential between the wheels with same bolt pattern. Seems like I should be fine. Am I missing any issue that is not specifically size related, like brake clearance. Much obliged for the help, mates.

jschrauwen

You'll be completely fine. The wheel width difference between your oem 09 summer S5 wheels and your winter 18" A5 wheels will account for the slight offset difference in the offset. The 2mm difference between 09 oem wheels and oem 16 wheels is very minor and I suspect this may be a very moderate change by Audi to accommodate a slightly more flush fitting to the fender lip as most enthusiasts over the years have been adding spacers to their oem wheels.
I'm assuming your concerns between the 16 wheels and A5 winter wheels involves potential ABS and TPMS concerns as your 16 no longer uses valve stem TPMS sensors to determine tire pressure. The key to this is to have the correct winter tire size on the A5 winter wheels so that it mirrors the exact same outside diameter as your 16 wheel tires config. Aside from that, I would confirm that both the 09 and 16 both use the same ball seat wheel bolts and not the conical type. If they're different then you need to use the correct seat type bolts for each.

DHS

You,sir, are a scholar and a gentleman. The difference in pressure monitoring was not even on my radar, nor was the bolt type. Much obliged for bringing that to my attention.
Cheers.

jschrauwen

You're most welcome sir.