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YOUR RESEARCHNew member with C4S winter question
Leading reported evidence
Run 17mm spacers
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I ended up running 17mm spacers on my rear wheels and that made everything look better.
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For example, my 10x18 wheels with a 47mm offset are used with a 17mm spacer.
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Suggestion
If you run the proper sizes recommended by Porsche, then your rear wheels will appear to be a bit sunken into the fenders.
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Suggestion
The recommended size for the rear wheel is 10x18, with a 265 width tire.
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Hi all, new member here. Bought a 2004 C4S cab last month, with 91.1K miles on it. I've been lurking on here since a few weeks before I bought it, and have been reading through the archives since, getting a feel for the particularities of the car, and the forum. I previously owned a 1985 3.2, sold it 10 years ago. The 996 certainly feels like a 911 to me!
I've been looking for winter tires and a hardtop, and a tire/wheel package has come up in Chicago, forcing me out of lurking and in to asking questions.
I see recommended sizes are
Front: 225 40/18 - wheel 8x18 offset 50
Rear: 265 35/18 - wheel 10x18 offset 47
I saw them on Craigslist, but I believe they are also here on rennlist:
https://rennlist.com/forums/parts-ma...7-chicago.html
Bridgestone Blizzak tires (Sport Edition Cup 4's from Tire Rack).
Same tire size as recommended above.
10x18 ET40 rears, 8x18 ET 54 fronts
So, my question is on the offsets. I'm not really a 'wheel guy'. Does the ET40 and ET54 specify the offset? If so, is that close enough to factory specs to run on a C4S? I'm more concerned with proper setup and handling than looks.
Thanks!
Oh, yeah, pics or it didn't happen. I suck at taking pictures, and the iPad also sucks at taking pictures, so combined...
Nice looking car. I drove my 996 C4S year round, and I did fit it with proper winter tires and wheels. The recommended size for the rear wheel is 10x18, with a 265 width tire. If you run the proper sizes recommended by Porsche, then your rear wheels will appear to be a bit sunken into the fenders. The story line from Porsche is that this was done to keep from having road debris and slush spray onto the rear fenders during winter driving. I ended up running 17mm spacers on my rear wheels and that made everything look better.
The "ET" numbers that you are seeing are indeed the wheel offset. You'll see them as "RO" sometimes too. Offset is a confusing thing sometimes, especially when you start adding spacers. You'd think that adding spacers would add to your offset. In reality, it subtracts from it because you're moving the hub surface outboard. For example, my 10x18 wheels with a 47mm offset are used with a 17mm spacer. This makes my effective rear offset 30mm, not 64mm.
I'm not sure what to tell you on the 54mm front offset of the wheels you found. Perhaps others can chime in. For you C4S, your bigger concern is overall construct (wheel + tire) diameter. The AWD system is sensitive to differences in diameters. For this reason, you should stick to the Porsche recommended tire sizes.
Good luck this winter!
Let me know how you survive the winter in your C4S, especially around Chicago.
One local member wrecked his in his first winter out.
I trust the equipment, just not other people...
Those offsets should work fine on a C4S. The tire sizes seem correct too. Your manual will actually specify the recommended tire size for winter, check it out.
Don't worry about driving around Chicago. I drive mine year round, last time I was in Chicago over the winter one of my favorite sights was seeing a new 991 4S on the road absolutely COVERED in road filth.
In the end even if something happens, the car is replacable, it's not a museum piece. The time you would waste not driving it while it is sitting in the garage is not. You wanted the car, you got the car, it is capable of driving in the winter to the point of the manufacturer actually giving you instructions about it, so go do it and have fun.
PS your picture is not bad. You're no Ansel Adams, but I've seen worse on here :-)
Thanks for the replies, everyone!
Looks like these will work for me. The car is my DD, but I have a home office, so I can usually avoid the worst/saltiest times. I just want to able to use it if I need it, and not let is sit all winter. I drive pretty safely in bad weather, knock on wood, and plan to avoid the city and rush hour as much as possible! Too many morons on the road...
