tecantolalala69

Hi, I need your help, I bought my first porsche 964 targa 1992 so I want to change tires but I want to put more size but I don't know what more so can you help me? The car brings with 205-55r16 front and 225-50r16rear

BLACK-BETTY

What is you wheel width/ J and your offset/ ET?

tecantolalala69

Is
Front 205/55r16 6jx16h2 52mm offset
Rear 225/50r16 8jx16h2. 52mm offset

Andy Roe

For the rear wheels I think you should be able to mount 245/45 R16, although I'm not sure if this is for 9J rims. This size has also been approved for use on the 964.

Andy Roe

Ok I've just checked and those have been approved for the 8J rims.

If you want to change to 17" or 18" rims there are more options open to you.

BLACK-BETTY

Wow that is a narrow J. Your 8J rears are smaller than my fronts at 8.5J!

8J I wouldn't go wider than 8J 235 and 6J 215 as the sidewall will bulge unless you don't mind. In which case I'm sure you'd clear 225 and 245.
If you want wider tyres I'd suggest getting wider wheels.

tecantolalala69

Black petty what about profile of front wheel and rear wheel, did you say me. 235 rear what profile? And 215 what profile?

tecantolalala69

Andy what width an profile do you recommend me in front wheel and rear wheel?

Andy Roe

I'm not sure what wider tyres you could out on te front. I run 17" rims and pulled the info for the rears from a doc I have listing the approved tyres in Italy for the 964. It doesn't mention anything different for the front than the 205's.

Andy Roe

Another thing worth mentioning is that if you have a C4 you need to be careful in your selection as the front/rear diameters need to be within a certain range of each other to avoid damaging the drivetrain.

BLACK-BETTY

I have no idea about tyre profiles for 16". However I would say that regardless of how wide your tyres are the profile/ rolling radius stays the same.

Of course rolling radius, I assume is slightly effected by width and tyre design but overall I believe you'd be within tolerance. Please don't take my word for it, as I'm not sure. Hopefully someone will chime in.

So in theory and from your above info,
215/55
235/50

tbennett017

^ +1 @AndyRoe

Mr.Alex

Are you running spacers? Seem skeptical that an 16x8 et52 clears oil pipe on its own.

BHCfarkas

lol you guys,... you realize he's asking about putting wider tires on the stock D90s, right?

bobaines

One option for you if you wish to go wider with the 16 inch D90 you will need to source a pair of 9 inch D90's. You can either search for a used pair, look on the 928 forum, or they are still in the system from Porsche. You can then fit 225/55/16 on the 8's in front and 255/50/16 on the 9's for the rear. These are within the 3% needed for a C4. I have these mounted on my C4 with no spacers. The car has been lowered on PSS10's.