Fikse FM-5 sizes for 930s

arrivederci · 05:03 AM

I'm taking the plunge and going for a set of Fikse FM-5s on my 930. I was thinking 18x8 and 18x10 with 225 40 R18 front, and 285 30 R18 rear. My goal is a setup that's not going to make parking lot maneuvers impossible, provides more rear grip (accel), and tire sizes that are readily available from multiple manufacturers (popular tires sizes). I also want these to fit without fender rolling/rubbing, and/or changes to the factory spacers.

What is everyone else running and what might I want to do differently? Its a lot of $$ to invest, so I want to make sure I get it right!

Bill Verburg · Bill Verburg's Garage

I hope that you meant 225/40x18 front. If so that would be a very nice set up/ w/ essentially stock tire heights. You can go bigger but as w/ 911s you will quickly run into interference problems after you go bigger than those sizes.

It looks like you may be thinking MPSCs or or Kumhos? If so the Kumhos have a bit of a height advantage(they are shorter)

dean · 06-04-2003, 05:29 PM

If I were you I would call Fikse and ask them also

arrivederci · 06-05-2003, 05:06 AM

My bad, Bill. Corrected...thanks!

I was planning on using these as street rims (primarily). My old 7x16 and 9x16 fuchs become track wheels for my '72. Therefore tire wise, I was thinking of using BFG KD's, or S0-3s. I put roughly 10K miles per year on my 930.

Bill Verburg · Bill Verburg's Garage

MPO is that the 18s are better suited to track usage and the 16" Fuchs are better suited to street use. One reason being potholes, another bing the available tire dimensions in each size.

I'm sure that whatever you do it will work out. Enjoy!!

thabaer · thabaer's Garage

I'd check the TIRE mfgs instead of Fikse. 18x8 is 18x8, as long as you know the offset there should be little variance from wheel to wheel even among different brands.

The rolling diameter and section width of tires is another matter, you can look up the revs/mile or similar characteristic at many of the tiremaker websites along with tread and section width. Armed with that, you can find 18" choices that will give you the same speedo readings and ride height, as well as get an idea if they are going to rip your fender lips apart.

I sized my 17" S-03s a few months ago like this, nice tires too after they broke in and limbered up enough to quit feeling like they were flat-spotted every morning