Have you ever wondered what the difference is between the Porsche Hollow Spoke Wheels versus the Solid wheels?
The Porsche 959 debuted with ground breaking technology that made its way into future generations of their production cars. Just look at the Porsche 964 AWD and the 993 turbo with AWD. What I found interesting is that Porsche offered the 959 with Hollow Spoke Magnesium Wheels even back then. I originally thought the Porsche 993 was the debut of the Hollow spoke technology but Porsche has always pushed the limits of engineering even back in the 1980’s. Amazing! I dont know if any other car company has applied this kind of technology to their production cars.
Perhaps its because the same weight savings if not better can be achieved with better manufacturing processes and materials today.
Porsche referred to their hollow spoke wheels as : Technology by Porsche.
Porsche offered the lighter hollow spoke wheels as well as solid spoke Turbo Look wheels on their production cars starting with the Porsche 993 models.
Both Options look identical from the front face but there are ways to tell the difference.
- Porsche part number
- The hollow spoke only used metal valve stems vs rubber valve stems for solid spoke
- The back face of the hollow spoke wheels were smooth
- The back face of the solid spoke wheels had ribs
Hollow Spoke Wheels: Smooth Spokes
When evaluating a car , always reach behind the wheel spoke to see if the back is smooth or ribbed.
The lighter and more valuable smooth back is the more desirable option.
Solid Spoke Wheel: Ribbed Spokes
Interesting cross section picture of the hollow spoke wheel
Hollow Spoke Wheels are 5-6 pounds lighter then their solid spoke wheels. The advantage is the reduction in unsprung weight which improves the car’s weight and more importantly its handling.
Porsche used the hollow spoke technology on the Porsche 993. Buyers had the option to choose the hollow spoke wheels vs the solid spoke wheels. The flagship model 993 Turbo came with the hollow spoke wheels as standard. These are referred to as Turbo I wheels.
Porsche 996 Turbos came standard with hollow spoke wheels while the Porsche 996 C4S received the solid spoke wheels.
The early production Porsche 996 Turbos were fitted with solid spoke (Turbo II) wheels as standard, and hollow spoke wheels were optional. The hollow spoke wheels would later become standard on all Turbos.
Here is a chart with part numbers to better identify the correctly wheels for your car.
TedMay 15, 2021
Thanks. This is great info. Porsche is amazing at what they do and seems the 959 was the grandfather of a lot of modern 911s. I have a 996 Turbo S. (Poor mans 959)