When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a very nice 928 S4 that I have been doing some light work on and its come out fantastic. I am thinking about going to a 17 inch wheel. It has the forged flat slotted discs on it
now in 16 inch. What at the popular choices which will work?
OFFSET
The one thing you are going to need to decide is how important maintaining the front wheel offset is to you. Your S4 has a 65mm offset. There were long conversations about the importance of maintaining this to preserve the correct scrub radius (read all about it). Some people follow this religiously some people have a broader interpretation on what is acceptable. Maintaining the proper front offset will greatly reduce your options
Wheel Size
Diameter: Porsche put out a technical bulletin about 20 years ago advising to avoid using 18" rims on the 928. Many of us have been using 18" rims for a long time without issue. Many of us have not found good tire options in the 16" diameter. There are plenty of performance tire in 17" diameter and even more at 18"
Width: There are also discussions on what widths you want. For the performance and track drivers, they try to minimize understeer and will want to put a wider tire/rim up front. The S4 will accommodate a 9" front (with some offset magic), but 8" rim will fit just fine. The rears of the S4 will accommodate 10" easily and 11" with some offset care as well
Wheel size & Weight: Just be aware the larger the wheel the heavier it is and the more it will negatively impact the perfomance of the car. Same goes for wider or taller rubber. Unless you are going with a Super Light forged wheel, upsizing will undoubtedly mean adding unsprung rotating weight to the very light stock setup.
A good recommendation is a 17" rim with 8" (~ET60) up front and 10" in the rear (~ET52)
Here are some common choices people end up with for 17" and 18" Porsche Cup I - 17" Porsche Cup II - 17" Porsche Carrera III - 18"
There are a few custom wheel manufactures that will be able to give you the exact dimensions you need and whatever face you like. Here is one of many: https://www.augmentwheels.com/
I will provide the contrarian viewpoint. I have an 86.5 car. It came to me with 18" Speedline replica wheels. It did look very cool but clearly not the way the car was delivered. I bought a set of 16" manholes. With the greater sidewall of the 16" tires, I found the ride comfort on long trips to be much improved. With the 18s, every joint in the pavement delivers a solid thump to the cockpit.
Panamera wheels are a great look on the 928 as they're a fairly simple design with a decent offset compromise of 8"x18" et 57 in the front, which are the same specs I run on both my 928s.
I dont like the squishy ride of a 928 with 16" wheels and OEM seats and prefer a firmer, sportier and more controlled ride, so I run 997 and 991 hardback sport seats with 18" wheels on both of mine. One is on Konis and the other on Bilsteins.
When I purchased my 89s4, it had 18" turbo twists. They looked awesome... but then I found that they were rubbing in the inner rears. I ended up downsizing to 17"s and have had zero issues.
I have a bunch of 928's and my favorite overall set up is the Carrera Lightweights in 8" & 10" x 18". They are on a 90 GT with the factory rolled fenders and quarter panels.
Another great option is the factory 17" Cup II's from a 94 or 95 928 GTS...
The Cup II's maintain a semblance of the stock look and give you some great tire options that the 16" manholes or D90's eliminate.
Here are the 18" Porsche Sport Design 2 piece wheels (an OE Porsche 911 wheel in the early 2000's, made by BBS) on a GTS 18 X 10 rear and 18 X 8 front. Rear offset is excellent, while front is 'acceptable' - gives great appearance (to my visual processing unit), but handling is somewhat compromised.
04-17-2023, 12:08 PM
928 S4 17 nch or maybe 18 inch wheel options
