Hop inside a 2017 Chevrolet Malibu 2.0T equipped with GM’s brand-new 9-speed automatic transmission and it becomes instantly apparent why General Motors has labeled the gearbox a “premium” unit: it’s as smooth as all get-out.
We had the opportunity to find that out for ourselves at a press event hosted by the automaker on Monday. Whether heavy or gentle on the throttle, the outcome was always the same; try as we did to count the number of shifts from 0 to 50 miles per hour, they were so smooth – the interruption in torque delivery so imperceptible – that we failed.
Of course, part of that is due to the simple fact that the new 9-speed automatic is taking smaller steps from gear to gear than most transmissions. Although the overall ratio spread of the Hydra-Matic 9T50 has increased to 7.6:1 from 6.0:1 in GM’s 6-speed transverse auto, most of the shifts occur in the lower end of the range, where one would otherwise be more likely to detect a noticeable jolt; smaller steps mean more minute changes in wheel torque.
We suspect that the other component of the new gearbox’s silky smoothness is simply symptomatic of brilliant engineering. Although GM – like all transmission-makers these days – has taken to locking the torque converter while the vehicle is moving, jerk is minimized through a combination of a spring-loaded mass damper, and the strategic use of “micro slip.” That’s where the torque converter is briefly unlocked to allow quick spurts of slip, permitting speed differentials in the range of 10 to 40 RPM.
Sadly, the Malibu doesn’t offer a fully manual mode of operation – at least, not that we could tell. We’ll have to wait to form an opinion of that function whenever we get the chance to experience the new 9-speed in a vehicle that does.
Nonetheless, you can color us impressed with how quick and seamless the shifts are in General Motors’ new Hydra-Matic 9-speed automatic. GM Executive Director of Transmission and Electrification Hardware Engineering Chris Meagher went so far as to say “you can tell [the 9T50] is premium,” thanks to “smooth” and “precise” shifts.
We see now what he was on about.