Exasperated Tire Post from non-OCD mod-free noob

Hi. I admire the way many of you obsess the details of your P-cars, but I simply enjoy the car as is. A weakness and perhaps even a moral failing, I know, but there it is. So my question is this. I have an '03 C4S. I purchased a set of bluidy snow tires and wheels on e-Bay from a '99 C4. My wheels are 18s. The snows are 17s. I figured I would need a set of spacers, but things should fit. Now my car sits forlornly at a tire dealership. They put the wheels on and the fronts are scraping the calipers. They don't sell wheel spacers. I called my Porsche dealer and they said call Tirerack. I did, and the dude at Tirerack said, "Well, we don't sell spacers, nor do we recommend putting tires on cars they were not meant for!" WTF? These are Porsche factory wheels. They were set up for an awd car. My car came standard with 17s, it just has the 18" option. So why is everyone acting like I want to sleep with their cat or something. I just want wheel spacers. I see you guys talking about them on this forum seemingly all the time. Can anyone please help? Thanks in advance. Oh, and I never changed my sig, but I am a paid member.

Sounds like you might have got a set of Boxster wheels. What are the offsets on the wheels?

If my memory serves me correctly, the C4S came with 18 inch standard. At least it did on my 993. Check the wheel offset. It might be listed right on the rim. If nothing else, give us the part numbers and we can tell you the offset. I suspect that all you will need is a set of 17mm spacers that Porsche DOES sell. They came on my TT with the Techno rims. If your dealer won't help you, contact Wheel Enhancements . They should have just what you need. Now just take a deep breath and relax. Cheers,

The C4 came with 17 standard. The C4S, however, comes with 18's standard. Even the recommended snow wheel and tire combo is 18". Among other reasons, this is to accomodate the larger calipers and rotors of the 4S. I'm not sure any kind of wheel spacer can offset the fact that it's the wrong wheel. Sorry.

Still a bit confused about this "wrong wheel" idea, though. As a non-modding person, I have always assumed (yeah, yeah . . . I know) that one could fit most any size wheel on a car if the bolt pattern was correct. I mean, it seems to me the first thing lots of people do to their rides is fit larger wheels, yes? Don't they frequently require spacers? My apologies if I'm missing a large boat here. I called my installer. Asked about offset. Got a message back, "Y'all need 'bout a quarter inch spacer." Not really the answer to the question, I take it. So ultimately the answer is that as a rank amateur, I should have bought from TireRack instead of e-Bay? Anyone need a set of 17" snows?

First of all....I don't think anyone here wants you to sleep with their cat. A bit of research would have been good here......but anyway, start by opening the manual & seeing the winter wheel recomendation. Knowing that, you can go up-down-sideways anyway you want but it's a 'calculation' rather than a crap shoot. Personally I like 17s......and, I like a narrower wheel & rubber than what Porsche recomends (for my winter snow). C4s are standard with 18s...........with Turbo calipers they do need clearance up front. That does not mean 17s won't work as long as the wheel size (8J ?), wheel offset, and wheel style, will accomodate that caliper. How much clearance do you need?........7mm spacers may be fine with longer bolts. What size are these wheels? (F/R).......what size are the tires?.....don't forget your front-rear size differential on a C4. What you have 'may' be just fine. I would not throw in the towel yet..........or agree to sleep with anyone's cat.

Your points are well taken. Though I actually did the research (I thought). Last summer I spoke to my dealer, wrote to this list and have saved various posts related to winter tires. But, you are right, I did not consult the manual. And I am red-faced now staring at the page which references tire sizes. Who would have thought? Ah, and here are the F&R sizes for 17" wheels! Complete with offsets listed! I never knew what an offset was. Damn my ignorance. Okay, so my front offset SHOULD be 50 mm. I don't have the snows here (the car is at the tire dealer), but I will check the offsets on those tomorrow. And that will tell me the size of the spacer I take it? Bluidy brilliant! Now, one final question. From looking at the spacers available, I am gathering that hub-centric spacers offer a clear safety and vibration advantage over the less expensive simple flat spacers?

If you put spacers larger than 5 mm you should really put in longer studs or else the bolts will not have enough threads to grab onto. Marc

Mark unlike the 964, our cars don't have studs. If anything they'll require longer bolts

Anybody care to tackle that one?

Well....... they will have 'studs' if you go to a fairly thick spacer (that uses the lug bolts to attach the spacer to the disc hat). Most anything over 12-14mm is avail in hub-centric with 'wheel nuts' for attachment to the spacer studs. OK......I don't have your manual in front of me (that lists 50mm as a 17" winter offset?).... so I can't tell if that's on an 8J rim (width) or what. Yes...........you can compute all this pretty easy...most people use this data (OE summer tire offsets) as a benchmark when modding.......ie they know 52mm is the OE offset on their OE wheels but they think the car would look better with the wheel 'out' 7mm or so more in the wheel arch.......so they buy a 7mm spacer (and longer bolts)........the net of this is 45mm offset..........When they save up bucks and order new aftermarket wheels, they will specify 45mm offset (and throw away their spacers). Hopefully you get the picture in your case. Having the OE spec can help you 'position' the wheel you've bought, approximately where Porsche was suggesting the Porsche-approved winter wheel would be (relative to the fender line, wheel arch, etc). Detail.......if spec is for 8J and you have 7J (7") remember that ev inch decrease in wheel width = 10-13 additional offset.........Also, all the above just gets you 'about' where OE approved wheel would be.........it does not mean you will like the way it looks, or that the 'wheel style' you have bought will necessarily clear your front calipers (but good bet it would). Good luck.

First, based on this thread both Riad and Yetis appear to use 17 inch wheels with a 996 C4S. https://rennlist.com/forums/showthre...=inch+snow+c4s Call Wheel Enhancement, as Fred suggested, tell them that you'd like to buy spacers from them, tell them which wheels you have and which car you have. They will tell you whether it is possible to make them work with spacers. Let us know what happens.

And by the way, Tirerack lied, they do sell spacers. They sold me spacers for my 18 inch wheels and snow tires that I use on my '03 C4S. 17 mm for the rear wheels. My car has sport techno wheels which came with a spacer but were slightly thinner. I would have preferred to have bought 17 inch wheels with snows if they do work with spacers (the whole package would have been $500 cheaper with the smaller wheels and tires and they are said to work better in the snow), but Tirerack said it's not possible, however, it now appears that they are wrong as Yetis and Riad as well as a friend of the guy that sold me my car all use 17 inch wheels and snow tires on a 996 C4S.

MANY places to buy spacers........Perf. Products catalog has 2 pages of spacers, nuts, studs, etc

Yeah, the only problem is that Performance Products probably doesn't know which size he needs (Tirerack didn't even think 17" was possible). This is a little bit of an emergency for him considering that the car is up on a lift without wheels. Make sure you talk to one of the guys that uses 17" wheels and snow tires with a C4S on this forum and find out which size spacers they use before ordering from Performance Products, it would be a shame to get the wrong size again and have to wait another week for the right ones. And even then, he still might not order the right spacers because the offset could be different on the other guys that have a C4S and 17" wheels thus requiring a different spacer.

For what it's worth. I run winter 17s on both the C4 & Turbo.........definately not the wheels he has (Strosek monoblocks) but they are 8Js with 50mm offset mounted with 235/45s........I use 7mm spacers for effective 43mm offset.

for the rapid-fire education in tire and wheel lore. I appreciate your help and all the information gleaned. I spoke to Dave at Wheel Enhancements and ordered 5mm spacers and lugs for the fronts. The rears fit as is. Now let me just say that Dave did not recommend this set-up, as he felt performance would be compromised in changing the track of the car. But reluctantly agreed that it wasn't a safety issue, it would work okay and for someone such as myself (no track rat, I) it would probably be just fine. Kudos to Dave. Oh, the actual tire size of my 17" snows: 205/150 7J x 17 55 mm offset. Thanks again for everyone's info and patience!

Good luck. BTW.........I've found that driving on snow or ice can also tend to "compromise performance" .