BMW has become the first carmaker to fit a series-production model with high-pressure cast wheels, introducing a new M Performance alloy for the M5 that it says removes up to 20 percent of the weight from each wheel without compromising performance. The 1075 M style wheels are produced using a process developed by Entec-Stracon GmbH of Aalen, Germany, which the supplier calls Turbu Pressure Casting. BMW claims the M5 is the first car in the industry to use the method.
The wheels will be offered in 20-inch and 21-inch sizes, finished in Gold Bronze or Jet Black, and sold only as a complete set with sport tyres. They fit the G90 M5 Sedan and G99 M5 Touring and no other model, and they go on sale this autumn through BMW M Performance Parts. Pricing has not been released, and US availability and pricing will be announced later. The tyre brand has also not been named.
Most cast aluminium wheels are made using low-pressure casting, a cheaper and slower method that is the main reason buyers seeking genuinely light wheels usually turn to forged alternatives. BMW's pitch is that its high-pressure process closes part of that gap while retaining the cost advantages of casting. In the Turbu Pressure Casting method, molten aluminium is introduced into the mould under vacuum and high pressure, with the wheel cast from the outside in within 0.05 seconds. Eighty sensors and an artificial intelligence system monitor the process, and demoulding takes only a few seconds.
Because the metal fills the mould so quickly, it solidifies with a smaller grain size, which BMW says makes it significantly stronger. Stronger metal allows designers to use thinner sections without sacrificing strength, and that is where the weight saving comes from. The process also opens up shapes that low-pressure casting cannot produce, including up to 70 bladed spokes, very thin aerodynamic sections, and finer contours and surfaces than cast wheels could previously achieve. Those figures describe the process capability rather than the 1075 design specifically.
A conventional cast wheel usually requires a separate heat treatment after casting. These wheels do not, which BMW says is a major reason total production time is cut in half, along with the energy needed to make each wheel. Entec-Stracon chief executive Ralf Bux put figures on that last year: 57 kWh per wheel, compared with the usual 114. BMW describes the material as an optimised, recyclable alloy. Entec-Stracon has said its process runs on 100 percent recycled aluminium, but BMW's release does not state whether the M5 wheels use fully recycled metal.
Weight saved at the wheel is more valuable than weight saved in the body. Wheels are unsprung mass, so the suspension must control them over every bump, and because they rotate, the drivetrain and brakes must spin them up and slow them down. BMW claims sharper handling, quicker acceleration, and better braking as a result. On a car as heavy as the M5, which weighs around 2,445 kg, any reduction in unsprung mass is welcome. BMW has not said how much a 1075 wheel actually weighs or what it is being compared against, so it is impossible to say yet how noticeable the difference will be on the road.
BMW can claim the first series-production car with these wheels, but not exclusivity. Entec-Stracon's second automotive customer is Mercedes-Benz: the new-generation S-Class, launched in January, rides on 20-inch multi-spoke wheels made with the same process, and the supplier says it can produce wheels up to 24 inches. That suggests the technology could spread beyond limited-run options on expensive saloons. If a wheel can be made with half the energy, in half the time, and still come out lighter, there is a clear case for it to become standard equipment on more mainstream models rather than remaining a parts-catalogue upgrade.