johnny1423

hi all...
i a bummed out
after owning and driving this car for 4 years ...i discovered today that my 18' sport design wheels are wrong(obvoiusly bought the car used)
fronts are 18x 7.5 et 50
rears are 18 x 9 et 52
These are friggin' boxster wheels I thought all sport designs were the same for boxsters and 996's....
they have always "looked" right to me..
I have never noticed....the car is a 1999 996..see pic
the questions are;
is the fit perhaps correct since this is an "early car"?
whats the different offset do..make the wheels stick more "out" or "in"?
will these damn boxster wheels fit my 1987 944 turbo?
what should i do??
thanks for your help in advance....

larry996

Yep, this is Boxster's size my friend.

PorschePRH

If you are happy with the way they look, don't sweat it. Just means you have to pay less for tires...

Offset is how much it sticks in/out from the wheel arches. Lots of people have different offsets and use spacers to change their offsets for the purpose of looks or to clear brake calipers with aftermarket wheels.

Botsy67

If I am not wrong (Tim or Dell can confirm...) but your front 50 offset is only 2mm out more which is OK and the rears are 13mm out-ward also OK, bc others (like myself) use spacers to push-out the wheels closer to the fender lips, up to 15mm or even 17mm on the rears and 5mm or 7mm up fronts. That's why your wheels do look fine on your car right now. The only downside is your Boxster rear wheel width being narrower, only 9" wide compared to 996 Spec of 10" wide. I don't know anything about the 944 T so someone else will chime in to answer your question.
Cheers,

Ray S

Those are Boxster wheels. You have a few choices.

- Keep running what you've got. Since they are 1" narrower the offset should not be a problem.
- Trade up to 996 wheels. Wheel Enhancement will take your wheels in trade and probably trade you for some 996 take offs (for a price).
- Buy new wheels

PorschePRH

Normal rear offset (on a 2003 C2 at least) is 65mm for rears that are 10" wide.

Since his are 9", that's 1/2" less to stick out which is .5 x 25.4 = 12.7mm

So he's only sticking out more if his offset is less than 65mm - 12.7mm = 52.3mm (less positive offset means it sticks out more).

So he's a whopping .3 off of factory offset...

Don't get caught up in all the precise specs for offset, wheel sizes, tire ratings, etc... People get too ****. Very few of us are racing Le Mans here...

Oh, and as much as I love to hate Boxters, there's an amazing amount of interchangeability between them and 911s, so don't feel so bad.

newport996

How do you drive your car? If you do alot of canyon carving, you may wanna get a set of 996 rears for the extra width and to run a wider tire....the factory sizes are 18x10 et 65 with a 265/30/18 tire. I would not go with a 285 with those fronts you will increase your understeer.

gota911

Correct.

His front wheels (7.5" with 50mm offset) extend 6mm farther out compared to an 8" wide wheel with 50mm offset.

His rear wheels (9" with 52mm offset) extend the same as a 10" wheel with 65mm offset as PorschePRH stated above.

johnny1423 - here is a link to a wheel offset calculator to help you get more familiar with wheel widths and offsets.

http://www.1010tires.com/WheelOffsetCalculator.asp

Hope this helps.

johnny1423

thanks guys!!!
so if i hear ya'll right...from looking down the side of the car ..my wheels actually sit out farther than if they were the correct wheels/offset...so the "missing" width is on the inside///right.
I think these will fit my 951..i will try to swap and see asap...
i guess i will start looking for wheels...
i feel i should stay wth 18's as i am afraid going to 19's will compromise the ride too much...
thoughts???
Thanks Again!!

gota911

Your rear wheels are "right on" compared to the "correct" wheels/offsets. The front wheels extend an extra 6mm, which is not much (only 1/4").

Most have said that 19" wheels ride more harshly, and that you will have less rubber between the wheel rim and the road (aspect ratio), and 19" tires are more costly. Still, that decision is up to you.

Carrera Mike

Stay with 18s. 996, specially your early model were not engineered to take the 19s.

newport996

There have been absolutely ZERO actual reports of 19's causing any damage to 996's....ZERO. With the amount of people running 19's on 996's you would think someone would have an issue if it was a problem.

Kevin H. in Atl..

Your fronts are the correct fitment for your '99 996.
The rears are not.
You could keep the fronts and trade/swap/replace the rears to 10x18 et 65 to obtain
factory fitment in the rear.

Carrera Mike

Its well documented by pro shops/porsche track prep shops, and even a big article in Excellence Magazine. Bumpsteer and allignment problems.

Ray S

I think you're both right...

Porsche did not engineer the 996 with 19's in mind. Additionally if you have 18's and 19's of similar design and manuafacture, the 19's will weigh more and ride more harshly.

However, there are certainly lightweight 19's available in the correct offsets for these cars (some lighter than the factory 18's) and plenty of guys are running 19's without problems.

Personally I'd stick with 18's as the 19's really offer no performance advantage over 18's. Then again 19's do look nice.

It would be pretty boring around here if we all had the same cars.