I need to order 4x tyres today and have a tyre size dilema

My 89 S2 came fitted with 17" Cup2 alloys http://www.porsche968uk.co.uk/images...lloy-wheel.jpgand I have no idea what car they came off or what the correct tyre size should be ?

I believe they measure 8.5" front and 9.5" or possibly 10" rear.

Currently fitted with front 225x45x17 and rear 255x 45x17

 

7.5" and 9.0" x 17"
Fronts are 225/45
Rears are 255/40

 

Check the inside of the rims for the correct size...measuring them will be wrong.

They should say 7.5J, 8J, 9J or 10J (for width) with the ET offset numbers.

Then...you can check Tirerack.com (or any tire/wheel site)...they know the correct sizings for 17 inch + vs. factory sizes.

I think Damian is correct as well.

 

I'm assuming he has genuine 968 Cup II's; I know in Europe you could get some odd widths for snow tires and the like. Here I've never seen 8 or 10J wheels, but since the Cup II's were shared with the 993 you'll see some 7J wheels kicking around.

 

is the wheel measurement taken between the rims ? doh !... I've been measuring the whole wheel width because the tyres are fitted .

Thanks for that confirmation.
Thanks for the replies ..............sorry I forgot to tick notification and only just seen your replies.
Its been one of those days ..........................................

 

If they are genuine the sizes will be stamped on either side next to the airvalve.

 

ah then these must be the replicas that I've read about .
thanks for that .