Well this is embarrassing (again)

I hope you all like answering questions as much as I like asking them. I hope sometime in 20 years I will have soaked up some of all the knowledge in the forum and can start answering some of my own. But for the time being I'm going to keep embarrassing myself: What is a spacer? I mean I can figure out the general idea but why is it needed? The reason I ask is that I've got a 986 S (see photo 1) and I've seen some nice wheels that might modernise the look a bit (see photo 2). The chap says I'll need spacers which is fine but if it's going to cause damage and a drop in performance then I'll forget it as I want to look after the car not damage it for the sake of vanity (I'm not not 18 anymore). Thanks guys. p.s. If anyone thinks the wheels look better as they are I'd be interested to hear.

Spacer are large "washers" that sit between the wheel and the wheel's mounting surface (hub). As you can probably imagine, they move the wheels outward from the car, creating a wider track. The distance of the move is dependent on thickness of the spacers. Any spacers thicker than ~5mm will come with longer lug bolts. If you're buying new wheels, I wouldn't opt for wheels that require spacers. Find a set that fits without spacers. You'll likely need a wheel with a different offset. Porsche sell spacers as an [expensive] option when ordering a car. But those are relatively thin.

Spacers give you a wider track, sometimes they make the car look better because the wheel fills out the wheel well better, and sometimes they make wheels fit that wouldn't fit otherwise. I put the thin OEM Porsche spacers on my car because they improve the look . . . a little bit. My narrow spacers didn't do anything for handling. Wider spacers might.

Thanks for the replies guys. The seller says that 18mm spacers with longer bolts or a 30mm spacer would be needed for the rear wheels. It does seem to me that the simplest option would be to look at a different wheel set.

That makes no sense, either spacer would require longer bolts and both 18mm and 30mm are huge spacers and will take away from the hub centering provided by the factory setup. Like others I would recommend getting a different set of wheels that don't require such radical spacers to fit.

The replies so far are spot on, but I'm a visual guy and here is a diagram to explain the offset and spacer situation. IMO, if it requires more than a 10mm spacer, I would look for different wheels. Good luck.

Order wheels that have the proper offset for your car. OZ makes a line of great wheel that come designed for our cars. Anything more than a thin spacer changes the suspension dynamics of your car from factory and increases the moment of the un sprung weight of the wheel.

Thanks for all the replies guys. I'm decided not to get involved with spacers. I'll check OZ out instead.

gfspencser - I was thinking of the 5mm spacers as an option for the same reason you mention but I talked myself out of it because it didn't seem like I'd be able to tell 5mm wider in the wheel well. Can you really tell the difference (i.e., any regrets or would you do it again)?

I've found a set of these 18" for a good price. BBS GT3 I think. These will go straight on I think?

Generally current Porsche wheels are made for Boxster/Cayman & 911 & are interchangable except to put REAR 996/997 wheels on a Box/Cay you must use a spacer since the REAR wheels are usually wider for 996/997.

I have the 5 mil spacers on my 06 CS and I . . . dunno. Someone very nice gave them to me for free when I bought my car a couple months ago, so I put them on because I certainly don't have any concerns about them. Surprisingly I do think they make the car look a little better--sometimes it's the little changes that give the result rather than radical mods. The rear tires especially now seem to match-up better with the outside of the wheel arch. At least I THINK I can see a slight difference :hilarious: As far as performance, I doubt anyone could tell. Five mm equals 0.4 inch, so it isn't much. Then again, look at setup changes made to race cars--they often come in very, very small increments. I will say that if I hadn't gotten the spacers for free, I would have a real hard time throwing down $500 (as Porsche charges) for them. If you don't have the sport shifter, definitely spend the money on that instead.

As 987 rims are not so common, I have fitted rims for a 997 and added 21mm spacers at the rear. The increased track width has only served to improve cornering grip levels.

As a side note; this may seem to be obvious, but remember that a 5mm spacer on each side equals a total of 10mm wider track, 10=20, 20=40, etc.