Porsche 911 - Do 997 Carrera III Wheels Fit Porsche 996 with ET57 Offset?

I've needed to replace the tyres on my 2002 Porsche 911 996 model and as the wheels also needed refurbishing I found that it could work out cheaper to buy a set of new (used) wheels with tyres rather than get mine done.

However it was then very confusing to try to work out if various other Porsche wheels would fit my car. In particular I'd found a set of 18" Carrera III wheels from a Porsche 997 and wanted to check if they were suitable. The information online was very limited and contradictory so it wasn't very easy to find out. Plenty of sites offered calculators to show offsets and wheel sizes but nothing seemed to be available that said "wheel offset x will fit your car".

Porsche 996 with Carrera 17" Wheels - 7J/9J ET50/ET55

For info the original standard factory wheels fitted to the Porsche 996 were Carrera 17" rims that were 7J front (7" wide) with 205/50 tyres and 9J rears with 255/40 tyres. The offsets for the wheels were ET50 for 7J front and ET55 for 9J rears.

The wheels that I'd found online were a set of 18" Carrera III/3 alloys from a 2007 997 Porsche 911 and had virtually new Michelin Pilot Sport N3 tyres fitted which would be £800 alone! The fronts had 225/40/18 tyres fitted and rears were 285/30/18. These had 2023 date codes so had clearly been fitted very recently. The wheels were 8J ET57 fronts and 10J ET58 rear and were immaculate condition having very recently been refurbished. They were painted black which wasn't my first choice of colour but for the price I couldn't refuse! 

Carrera III/3 alloys from a 2007 997 Porsche 911

My previous 1998 Porsche 911 Carrera 2 had 18" SportDesign/GT3 wheels that were 8J/10J so I knew that 18" wheels would fit as it was also a factory option. The big difference was that the factory 18" wheels had offsets of ET52 and ET65 for front and rear. These 997 wheels were offset ET57 and ET58 so it wasn't obvious that if they fitted the car whether they would rub the suspension struts or the wheel arches.

Do Porsche 997 Carrera3 wheels fit 996 Offset ET57/ET58?

Having purchased the wheels I can confirm that they do fit the car. The 997 Carrera 3 rear wheels are a perfect fit on a Porsche 996 but the fronts are a little recessed as the bigger offset puts them more inside the wheel arch. They don't rub and can be run as is but I've decided to fit 5mm spacers to the hubs to put them back to the same position as the original factory wheels.

Overall I'm very pleased with the way the wheels fit and look on the car. The black colour is growing on me but even if I decide to change to a silver set in the future I have a new set of tyres that would have cost me £800 to buy elsewhere.