Need clarification on 18" wheels

[utkinpol]

Hi,

I have regular 2006 997 C2 for about a week now. It came to me on regular carrera classic rims, standard size - 18x8 front and 18x10 rear. With winter tires on them. So I started shopping for new set of rims.

I still cannot get proper idea of what rim sizes do fit into C2. One wheel dealer told me C2 can take up to 12" wide rear rims.

I see regular option for rear is 19x11 inches.

I have a friend who has his 18" 996 turbo rims for sale. but I cannot get any sort of confirmation if widebody 996 turbo rims can fit 997 C2. I also do not see any option on tirerack for 18" rims wider than 10". Is there any specific reason why 19" rims can go 11 and 11.5" wide and 18" rims cannot?

I wanted to get 18" lightest rims preferably 11" wide so I could mount 295 or 305 wide tires on them. I do not care about 19" or 20", just want light rims and wide tires.

Can I do that on C2 or not? Can anybody explain all that to me please? What offset I need and what options do exist for that?

[Loren]

There is a TSB that calls out the wheel and tires sizes that fit narrow body cars. 11.5 " rears will fit but 12" is not on the list.

There is a separate TSB for wide body cars.

[PAULSPEED]

The 295 fit the 11 inch wide tires.

The 305 can go on an 11" but a better choice is a 11 1/2"

wide wheel.

The 18" tires have more choices when it comes to slick (race)

tires.

The 19" inches do not have as many choices for slick tires.

This is the reason you will see more lightweight 18" wheels.

Paul

[utkinpol]

The 295 fit the 11 inch wide tires.

The 305 can go on an 11" but a better choice is a 11 1/2"

wide wheel.

The 18" tires have more choices when it comes to slick (race)

tires.

The 19" inches do not have as many choices for slick tires.

This is the reason you will see more lightweight 18" wheels.

Paul

My question was mostly about what exact offset, backspace should 18x11 rim have in order to fit properly into regular 997 C2 car?

It is not as clear as I expected that to be, couple places i called could not answer that for me. Everybody seems to know sizes for 19" rims but not for 18".

[Loren]

The 295 fit the 11 inch wide tires.

The 305 can go on an 11" but a better choice is a 11 1/2"

wide wheel.

The 18" tires have more choices when it comes to slick (race)

tires.

The 19" inches do not have as many choices for slick tires.

This is the reason you will see more lightweight 18" wheels.

Paul

My question was mostly about what exact offset, backspace should 18x11 rim have in order to fit properly into regular 997 C2 car?

It is not as clear as I expected that to be, couple places i called could not answer that for me. Everybody seems to know sizes for 19" rims but not for 18".

As I said it is clearly stated in the TSB. Contributing Members here have view access to all the Porsche TSBs.

According to the TSB - Porsche does not approve a 18 x 11 wheel for the 997-1. In 18" wheels only 18 x 10 is approved.

[Singe]

TSB 02/06 4440 has 11" wheels approved for narrow body cars.