Porsche Enthusiasts Club Forum

Hi Porsche Enthusiasts

I am thinking of buying the following 18 inch alloys

Front wheels: 8J x 18H2 - ET57
Rear wheels: 9J x 18H2 - ET43
Front tyres: Pirelli Snowsport 235/40 R18 91V N0
Rear tyres: Pirelli Snowsport 255/40 R18 95V N0

I would be grateful for some advice.

Would I be able to fit these straight on?
Would I need spacers?
The rear profile is 40, would I need 35 tyres instead?

Any other help would be appreciated

Your going to need a spacer on the front and I think the rear is going to be very close to the bodywork.

Thanks Sean, so it is possible?

I thought I will probably have to get new rear tyres maybe... 35 instead of 40?

These are winter tyres, not sure I see the point of winter tyres this wide on a 944. Winter tyres generally work better when narrower than the summer fitment. Having 18" winters is a waste as well.

I agree, Jim. Wide tyres in snow are a disadvantage. I always fit narrower "winters" than my standard summer tyre.

Yes I will swap the rear tyres to a 35 and narrower rear tyres... I have 255s on my 17s at the minute and thats possibly a contribution to spinning it into a barrier...

I wanted new wheels anyway so I am going to replace them whilst getting the bodywork repaired.

What tyres would you recommend to go on the rear wheels? For all year round use? I only use the S2 at evenings and weekends.

Narrower Tyres aren't going to sort out the extra hang of the wheel on the hub.

If handling is a consideration, put 16's back on the car. I guarantee it will handle so much better.

I definately want the 18s. What tyres would you recommend for this wheel?

Generally you would put

205 on 7"
225 on 8"
245 on 9"
265 on 10"

The std offset from memory is 52 so your wheel is going to sit out further than designed. The standard wheel size on an S2 is 16 x 8. A larger wheel will fit but you usually fit a higher offset and then space it out to fill the arch.

It might look the business with 18s but it will drive like a pig, listen to the above

You can lead a horse ........,,

Haha I appreciate the thoughts and advice.

I've heard a mixture of opinions on putting 18s on the 944. Are we saying the ride will be affected or the car will actually be damaged in the process? As I really will not be spending much time in the car.

Factory Technical Bulletin #9305 of April 15, 1993 "Retrofitting of 18" wheels on Porsche vehicles which do no have 18" wheels as original equipment is NOT ALLOWED (bold and underlined!).

The factory says that endurance tests have shown that equipping certain Porsche vehicles with 18" wheels in an application not already approved by Porsche Cars may result in loosened bolts and/or threaded connections on the front wheel carriers. This, in turn, may cause fractures in these components. Fractures may also occur in the front strut mounts and in the body in the area of the rear suspension as a result of the installation of 18" wheels.

Such damage can occur without warning.

This bulletin applied to ALL models of cars.

Also of interest is Technical Bulletin #9303, September 28, 1993, which deals with the fitting of 17" wheels and tyres to 4-cyl models from 1987 onward, 944, 944S, 944T (all with M30 option), Turbo S 1988, Turbo 1989, and S2 from 1989.

Fitting of 17" wheels on vehicles previously equipped with 16" wheels is allowed, however you should also replace the caster adjustment parts so that the alignment can be adjusted for the proper caster angle of 3 deg 15-45'. The parts needed are:

Rear Mount 951 341 023 00, 2 each
Eccentric 951 341 431 02, 2 each
Bolts, 4 each

Also if you are defying specific manufacturers safety notices, you may find in the event of a claim you could be uninsured.

One more time, 968 turbo S and RS.