ypshan

I just received the winter wheel/tire package from Wheel Enhancement. The shipping invoice says 10x18" wheels. However the Porsche owner's manual says 10Jx18 wheels are required for winter tires at the rear.

What does the "J" mean? Did I receive a set of wheels that are half an inch short? If so, how come the 265/35 R18 tires that came with them seem to fit fine?

Thanks.

ypshan

Cjv,

If you look at the Porsche publications (both the owners manual and the bouschure), they use both J and X together. E.g. On page 206 of the owner's manual, they printed the front at 8J x 18.

That led me to wonder if the "J" means something like half an inch. Then I tried the following math on the rear tire:

11.5 inches * 2.54 cm/inch = 29.21 cm

That's pretty close to the 295/30 R18 spec. of the 295mm tire width.

However, the front calculation doesn't foot.

So I am back wondering what that "J" means.

JohnM

The "J" refers to the shape of the rim in cross section.

Footnote: most alloy wheels have this rim shape, so the J is on just about everything - consequently it is often omitted when referring to the wheel dimensions.