? About my tires

[911Brian]

The PO put 17 inch turbo twists on my 80 SC. The tire sizes are

Front: 205/50 R17
Rear: 255/40 R17

I have been reading about all the different combos and gearing etc. but I am a bit confused. Will this configuration pose any problems?

[Bill Verburg]

Only a small amount of gearing hit. The optional wheel and tires for your year were 6 & 7 x 16 Fuchs w/ 205/55(24.9" tall) & 225/50(24.9" tall) x 16tires

Your 205/50x17 is ~25.1"tall and the 255/40 is also ~25.1"

So your gearing hit is < 1%

If they are real turbo twists(hollow) there is ~6-8# weight hit(between the wheel and tire)) at each corner. That isn't good but it isn't that bad either.

For these negatives you get a wider hopefully stickier and hopefully better looking package.

[masraum]

The only thing that I can see from that combo is increased understeer because the front to rear to front width ratio has been changed.

Those tires should be virtually the same height as the stock size 16's, so there shouldn't be a problem with gearing or speedo. They will most certainly be heavier which will hurt acceleration and handling some, but many people have done the same mod, so it must not be too bad.

The only other thing that I ever hear about is the increased stresses put on the hubs, bearings, etc, but I believe that is usually associated with 18" more than 17" wheels.

[911Brian]

Thanks for the input. Here is a pic of the car. I would imagine that they are the real Turbo twists.



Thanks!