golfman

Which size wheel spacers would you use to configured the stock 18" carrera wheels to be flush to the fender like the 19" wheels. I know there is a 1" difference in wheel diameter between 18" and 19". So would I use a 1" spacer? Porsche only sells the 5mm spacer. Which doesnt seem that big. There are other companies that sell much larger ones that I could order.

Rolf Stumberger

Spacers have nothing to do with wheel diameter.
They are used to offset the wheel farther away from the hub.
Check the WIDTH of your wheel vs. the 19 inch wheels. The difference
is the width of the spacers you want.

golfman

Ok, That was my question. If I move the stock wheel that is 10" wide out with a 1" spacer will it then sit as far out as the 19" wheel that is 11" inches wide with no spacer.

Chris C.

Depends on the offsets involved, see here... http://www.1010tires.com/WheelOffsetCalculator.asp

Plug in the offsets and widths of the 19s vs 18s.

Porsche is very conservative with their offsets on these cars. First thing I did was change to forged wheels with better fitting offsets

Porsche spacers have their own studs and are high quality but expensive. H&R has a line of spacers that are more reasonably priced (and also highest quality)

MJones

Using a Wheel Offset Caculator :
The difference between 18" and 19" are as follows:

Front = the same
Rear = 4 mm narower per side with 18" vs 19"

A 5mm spacer would make the 18" sit 1 mm wider per side

golfman

Cool, That was what I was looking for. That must be why they sell a 5mm spacer. Now the big questions is how well do the stock 19'' wheels fit the rear fenders?

golfman

ok must be stupid can't figure out how to use this calulator at www.1010tires.com

MJones

Porsche wheel sizes are listed as follows:
8.5J x 19 RO 56
The last number is the offset
Width and offset are also cast into the wheel at the valve stem area.

ngregson

This is good timing...I was about to post the same question. I have a C2 which came with the 18"s. I replaced with 19's but kept the 18's for snow tires, which I will be putting on in the next few weeks. I wanted to fill out the wheel wells with the 18's, so it sounds like a 5mm spacer would do it? I presume I could also go a bit wider to enhance the looks without any significant detriment to handling. Anyone have any advice as to how wide (spacer size) is enough/too much?

Thanks

Nigel

golfman

Ok maybe this is the problem then. I am looking at Tequipment 911 book that has wheel sizes and offsets on stock wheels. It says 18" rear is 10" wide and 58 offset for carrera III wheel and 8" wide front with a offset of 57. It lists the standard 19" carrera S wheels as 8" wide front offset of 57 and rear 11" wide and offset of 67. When you use the calculator on www.1010tires.com do you add to the offset or subtract from it if you use a spacer? I subtracted 5mm from the offset and it shows the 18" would be 1mm extended now. Is that right?

gota911

Golfman - since the spacers push the wheel outward, you have to SUBTRACT the spacer width from the inner clearance and ADD it to the Outer position. Below is a screen shot from www.1010tires.com with this simple example:

Going from 10" wide with 65mm offset
Going to 11" wide with 65mm offset.
Result:
Inner clearance is 13mm LESS
Outer position is EXTENDED an extra 13mm

Let’s say you want 5mm spacers with the new 11" wheels. The Inner clearance would be 8mm LESS (than the original 10" wheels) and the Outer position would be EXTENDED an extra 18mm (compared to the original 10" wheels).

Hope this helps.

golfman

So you subtract the wheel spacer from the offset. if it was 58 offset withoutthe spacer it would now be 53 with a 5mm offset

Chris C.

Nigel - Porsche has used spacers as large as 17mm for factory fitments, which presumably means they have no ill effect on street driven cars. Many feel that spacers should not be used on the track due to extra load on the axles and bearings.

If I were going to add spacers I wouldn't waste time/$ on 5mm ones - it's just not that noticeable. For example - I replaced my Boxster's 19" rear lobster forks with wheels the same width but 13mm lower (meaning farther outboard) offsets and they perfectly match the rear fenders. The front offsets are 7mm lower.

gota911

Correct!

golfman

Well I ordered a set of 15mm spacers last night for the rear. I ordered from vertexauto.com. Since they are a sponsor here and the deal was pretty good. Hub-centric spacers $99.00 a pair. That also included the 10 lug nuts. Now if this works out, I will probably order a 5 or 7 mm for the front. I don't think there will be a problem. I have 18X10" wheels on there now and I have read that several people are using this size spacer on the rear with 19X11" wheels.