If there is something to look out for from General Motors aside from its new vehicles and engines, it is its new nine-speed transmission. Yes, you’re reading it right, GM now has a new nine-speed transmission for its passenger vehicles, and it will make its first appearance in the new Chevrolet Malibu.
In particular, this new nine-speed transverse Hydra-Matic planetary automatic transmission Hydra-Matic 9T50 – developed by GM itself – will debut on the 2017 Chevrolet Malibu Premier that is powered by 2.0-liter turbocharged engine. It will also be available on the 2017 Chevrolet Cruze that is powered by a 1.6-liter turbo diesel engine and the 2018 Equinox with a 2.0-liter turbo powerplant. Also, GM’s Hydra-Matic 9T50 nine-speed transmission will be available to seven more models by the end of 2017.
This new Hydra-Matic 9T50 is derived from GM’s existing six-speed transverse automatic gearbox. GM will manufacture the Hydra-Matic 9T50 at its San Luis Potosi site in Mexico. While GM developed the Hydra-Matic 9T50 to be employed in front-wheel-drive passenger vehicles – both gasoline and diesel-powered – this nine-speed automatic transmission is also ready to be used in four-wheel-drive units.
According to GM, the new Hydra-Matic 9T50 is more fuel-efficient than its current six-speed automatic transmission. As Chevrolet claims, a Hydra-Matic 9T50-equipped Malibu returns an EPA-estimated fuel economy rating of 33 mpg highway, which is around three-percent better than the 2016 Malibu fitted with the eight-speed automatic gearbox. Dan Nicholson, GM vice president for Global Propulsion Systems, remarked that the new 9T50 also offers a strong overall balance of performance and refinement.
Compared to the existing six-speed transverse automatic, the Hydra-Matic 9T50 is around 10 kg (22 lbs) heavier as it contains more planetary gearset and relevant parts. Since the packaging for both transmission is more or less the same, the Hydra-Matic 9T50 could be used on models where the 6-speed is fitted. Because the Hydra-Matic 9T50 has more ratios, it could better match the engine with the most suitable forward gear.
In fact, the Hydra-Matic 9T50 boasts of a wider ratio spread than its 6-speed predecessor (7.6:1 versus 6.0:1), with 4.69 on the first gear and 0.62 ninth gear (overdrive ratio). Aside from the ninth gear, the eighth gear also features a 0.75 overdrive ratio. The 1:1 ratio is achieved on the seventh gear, which means that there are smaller steps between the gears. According to Nicholson, this allowed the Hydra-Matic 9T50 to offer smooth and almost imperceptible upshifts.
While the Hydra-Matic 9T50 is GM’s first nine-speed gearbox for passenger vehicles, it is not the first carmaker to offer one. Land Rover and Jeep employ their own version of ZF’s nine-speed transmission while Mercedes-Benz has the 9G-Tronic gearbox. Ford, meanwhile, employs a 10-speed transmission in the 2017 F-150 Raptor. Interestingly, GM shares the design and engineering of the Hydra-Matic 9T50 with Ford. In exchange, GM could employ a Ford-developed 10-speed longitudinal automatic transmission in the Chevrolet Camaro ZL1.