How transmission gear ratios influence the acceleration and feel of a car
The internals of a manual transmission play an important role in the driving characteristics of a car. The Ford Mustang’s six-speed manual recently received a gearing update, and Engineering Explained released a video studying the effect of these changes on the transmission and the car’s overall behavior. Whether or not you’re in the market for a Mustang, Jason Fenske’s explanation is a great look at the inner workings of a manual gearbox.
A manual transmission starts with the engine’s power and, through the use of multiple gear pairings, multiplies the torque to allow a combustion engine to propel the car happily at varying speeds.
The example Fenske chooses to illustrate this dynamic? Comparing two Ford Mustang GTs, from the 2015 and 2020 model years. (The newer pony has 460 hp, versus 435 hp when the current-gen Mustang GT first launched.) The gear ratios in the transmission vary between the two models, with the newer Mustang showing more linear acceleration across the gears. The illustration in the upper left of Fenske’s infamous whiteboard is a wonderful illustration of how the gear ratios lay out. The 2015 model has a tighter grouping in the lower gears, with a large jump to sixth gear for highway cruising. The 2020 model has a more linear progression in its gear ratios all the way through top gear, which causes the car to feel slower across the board despite the fact that the 5.0-liter V-8 engine in the 2020 model produces an additional 25 hp and 20 lb-feet of torque.
We reached out to Ford for specifics on the manual-equipped 2020 Ford Mustang GT’s 0-60 and 0-100 mph times versus that of a so-equipped 2015 model. A spokesperson would not officially comment on specific figures, but he was able to confirm that the 2020 model is indeed faster in both measurements.
In Fenske’s estimation, Ford’s update to the Mustang GT’s gearing “ruins” the acceleration. Whether you agree or not, Fenske lays out his case very smoothly and with the power of brightly colored markers and math. In the end though, from where I’m standing, it’s hard to complain about the Mustang’s gearbox when it still includes a clutch pedal—a dying option. It might not be the best, but it’s there, and we appreciate Ford for keeping the flame alive.