Motofreak48

Looking to see what people are typically running on their UrS4's


I'm picking one up in a couple weeks and looking for some summer wheel/tire options.

Thanks!

UrS4boy

Your question is a bit like "How high is the sky?" (Answer = It depends on your definition of....." )

In this case, it depends on your driving needs, the brake system used and the suspension set-up, e.g. lowered, stiffer springs, etc.

Stock wheels are 16" and stock tires are 225/50/16 for an overall height of 24.86 nominal inches. 245/45/16 is only 0.7% shorter than stock at a diameter of 24.68 inches.

The next wheel size up, 17", is common when going to larger brakes, e.g. Porsche 928GTS "Big Blacks", needs 235/45/17 to stay within reasonable range of the stock size, i.e. 25.33 in is 1.8% taller than stock. 235/40/17 is about 1.19% shorter than stock.

Going to 18" can be problematic if the suspension is stiffer than stock because now you need a very short side wall tire to stay close to the OE diameter, e.g. 245/35/18 is just 0.4% shorter than stock but the ride harshness can require kidney belts.

Motofreak48

It is a bit wide open, but thats the point really

I recall clearance issues with my '94 100CS going with anything wider/bigger than a 225/45/17.

Which is also what I am looking at right now for the S4. I know the S4/S6 has wider flares, and if that can accommodate a wider tire, that's the kind of info I'm looking for.

My car has the stock brakes, with Bilstein shocks, so the ride height is a pinch lower. It's going to be my daily with weekend road trips and some spirited weekend mountain driving.

I was looking at sticking with the 225/45/17 as it worked well for me in the past.

UrS4boy

What never came into this conversation was the ET (off-set) of the wheel and the wheel width. All four OE UrS wheels were in the ET37 to ET40 range and widths in the 7.5 to 8 inch range.



Here are the tire sizes that the factory thought were best with those 15, 16 and 17 inch factory wheels:



On my German spec 1994 UrS4 V8 avant, I am running 4A0071495 1ZL 8J x 17s ET 35 (5mm further out than ET40) Votex Accessory Boleros with 235/45/17 Continental Extreme Sport DWs on them and there is no outer edge conflicts with the fender. I went with 235/45/17 instead of the factory recommended 245/40/17 because the avant has been lowered (too far) and the 235/45/17s were slightly taller = less scraping on parking lot speed bumps. The Conti Exstreme DWs were recommended by others along with Michelin Pilots (too expensive for me).

Motofreak48

Excellent! Now that's the kind of answer I as looking for...a little more than less. LOL!

I love the wealth of information my friends, thank you so much! It's been awhile since I have dove into the car scene and I forget how much more information there is regarding upgrades compared to motorcycles.

The Fuchs wheels are currently installed on the car I'm buying, which will be my winter rims, for those times I need them.

Question is, will a 235/45/17 f0r a 17x7.5 rim? I'm looking at buying a set of Advanti 15 Anniversary wheels that are 17x7.5...

Also, will the 235 give me more performance over the 225?

Thanks so much for the help and information, it's much appreciated.

UrS4boy

Yes. Or a 17 x 8 rim as well. Make sure that the ET offset of these wheels is between ET 35 and ET 40 and the the bolt spacing is 5 x 112.

235 is a bit wider that 225 so there should be a bit more grip. However, the tire compound will be more important. If you want performance, don't buy tires with a tread wear index higher than 300. They will be too hard.

Motofreak48

Perfect. I'm going with the Conti Extreme DW after doing my research. It helped that you're running the same tire on your Avant Going to give the 235's a whirl.

35mm offset of the wheels as well, looks like we are golden. I'll post up some pics once I get them installed.