15" vs 16"

[82SC]

I have seem some people use 15" on theor porsches even later SC...

and these have been project cars..money no object...etc...

is there any advantage to this?
were the earlier turbos 15" 7" and 9"???

MJ

[Bill Douglas]

With low profile tires on a 15" it gears it down a little. I have 16" on my SC and think 15" don't look right on a SC or newer.

[Early_S_Man]

The 3.0 Turbos came with 7 and 8 x 15 Fuchs wheels, and Pirelli P7 tires of 205 and 225 cross-section!

[Reg]

How would 15 x 7 fronts from either a turbo or SC look on my 70 t all the way around, shod with 205 50 15's?

Is that offset ok for the rear on my early car? Maybe some fender rolling in order?

I have 16 x 6's now to go on , but would rather buy 15 x 7's for broader tire choices, after all 205 50 15 is a popular size.

Anyone want to trade ?

[car911]

I switch between 15" and 16".

Actually, for city driving, I prefer the 15". The lower gearing effect makes for more lively shifting. You notice the decreased stability in hard corners etc but you don't do that kind of driving very much on city streets.

[RLJ]

You asked about wheel size not tire size here and this is MHO.

15" wheels on my early car were the hot setup years ago! I had 7 & 8 x 15's reconditioned for my car. I wish now I would have done 8 & 9 x 16" or even 7 & 8s x 16. There are fewer and fewer tire Mfg's that are making FAST 15" tires.

If I had it to do over again I would buy 8 and 9 x 16" Fuchs, have Harvey Weidman refinish them like RSR wheels. I think they would look awsom on "Iris".

Randy Jones
1971 911

[Reg]

Randy,

From an autocrossing standpoint, wouldnt a 205 50 15 be sufficent for a T , if it were competing in "stock" class? I can play with rim width in stock class in Canada, also can change shocks too!

That size is readily available in R compound.

It should be well enough grip for my light, low powered car don't you think?

[JAE]

I had 15" 7's & 8's on my SC. I just picked up a set of 16" 7/8's- I like the look a lot better and there are a lot more tires to choose from. I can't tell much difference in acceleration and cornering during normal driving.

[Randy W]

Gearing and clearance (on narrow bodies cars) are the advantage to 15" wheels. Many SC and Carrera autocrossers use 7 & 8x15s for the short courses or in the rain. Pre '75 narrow bodied 911s already have low gearing, so the advantage for them is more one of increased fender clearance with the same aspect tire. As Randy Jones has already mentioned, the hot set-up was (and in some peple's minds still is) 7x15s all the way around with 205s on an early 911 - this should work well for you, Reg, in your stock class. I have also seen more and more SC/Carrera owners going to the wider 16" Fuchs and 17" custom wheels so they can have more choice in tire compounds.

Happy T Day Randy!

[Reg]

Thanks to both Randy's.

[J P Stein]

I looked for 7 X 15 Fuch for some time and didn't find many. Why?

Near as I could figure, it's because Kumho makes their Victoracers in 205 X 50 and 225 X 50 in 15 inch but not 16 inch. I hear this is going to be corrected in the near future.

These are not the ultimate autocross tire, but you can drive them to the event and probably get a season out of them.

I ended up with some cast BBSs and the Kumhos are great.

[RarlyL8]

Consideration should be given to how you use your car.
I went with 15" wheels to allow for a greater sidewall height. This gives a better ride on a street car. It also allows the overall tire hieght to be low enough for proper gearing. If the car is lowered the visual effect is still good.

If you don't mind a more harsh ride, or you want optimal performance, a 17" wheel is better on an SC or later car. Tire sizes seem to be more limited in the 16" size than for 15 and 17.