3 Ways the New 10-Speed Automatic Improves the 2018 Ford Mustang

While many automakers have gone to 7-, 8- and 9-speed transmissions, the 2017 Ford Mustang is only offered with a 6-speed manual and a 6-speed automatic. That will change with the arrival of the 2018 Mustang, which will feature the new 10-speed gearbox as the only automatic transmission in the option list. This transmission was developed jointly with General Motors, and in addition to the 2018 Mustang, some variation of this gearbox is employed in the new Ford F150 Raptor and the new Chevrolet Camaro ZL1.

The decision to transition the 2018 Ford Mustang entirely to the 10-speed automatic (along with the continuation of the 6-speed manual) has raised some question from those folks who are unfamiliar with these newer transmissions with more than 6 gears. While I have not driven the 2018 Mustang with the new 10-speed automatic transmission, I have driven a wide variety of other vehicles with 8- and 9-speed automatic transmissions and based on those experiences – the move to the 10-speed in the 2018 Mustang should only be a good thing.

Don’t listen to the uninformed skeptics – the addition of the 10-speed automatic transmission to the 2018 Ford Mustang will improve America’s in every way, but for the sake of discussion, I have narrowed the upsides down to three specific areas – performance, fuel economy and drivability.

Why the 10-Speed Makes the Mustang Better
To understand how the new 10-speed automatic transmission will improve the 2018 Ford Mustang, you have to first understand how the 10-speed gearbox differs from the old 6-speed automatic, shy of the simple fact that it has more gears.

Acceleration
With every transmission, the engineers have to work to balance performance and efficiency. Steeper gearing (numerically higher) offer better acceleration, but those steeper gears lead to higher engine RPMs and higher engine RPMs lead to increased fuel use and lower fuel economy. This is why the numerically lower gears have numerically higher gear ratios while the numerically higher gears have numerically lower ratios. This allows the vehicle to accelerate more quickly in 1st through 3rd gears while gears like 5th and 6th offer less acceleration but improved fuel economy.

For example, the current Ford Mustang GT with the 6-speed automatic transmission has the following gear ratios:
1st 4.17:1
2nd 2.34:1
3rd 1.52:1
4th 1.14:1
5th 0.87:1
6th 0.69:1

Those ratios allow the Mustang GT to accelerate hardest in 1st gear and with each shift, the decrease in gearing leads to less acceleration forces, but also decreased engine RPM and decreased fuel consumption. The “trick” is that the engineers need to balance low end acceleration with decreased fuel use, but they also need to pay close attention to the change in ratio from gear to gear. Too aggressive of a change can lead to a big drop in engine RPM, which could take the engine out of its key powerband.

Realistically, the current Mustang GT with the automatic will pull hard through 4th gear, but in 5th and 6th, the overdrive gear ratios lead to substantially slower acceleration.

On the other hand, the gearing of the 10-speed automatic transmission in the 2017 Chevrolet Camaro ZL1 is as follows:
1st 4.70
2nd 2.99
3rd 2.15
4th 1.80
5th 1.52
6th 1.28
7th 1.00
8th 0.85
9th 0.69
10th 0.64

Now, the 2018 Ford Mustang might have unique gear ratios in its 10-speed automatic compared to the Camaro ZL1, but we can expect that the numbers will be relatively similar. First gear in the 10-speed is steeper than 1st in the 6-speed, and the same is true of every other gear up to 6th. The 10-speed doesn’t get to an overdrive gear until 8th, so the 2018 Mustang with the 10-speed will almost certainly offer improved acceleration through every gear.

Drivability
Next, since there are far more gears for the engineers to work with in the new 10-speed, there are much smaller steps between each gears. This means that in normal driving situations, shifts will be harder to feel or hear, as the shifts are smoother and the RPM change is far less substantial than in a Mustang with the current 6-speed.

Many people believe that with one of these new automatic transmissions with 8, 9 or 10 gears that you will constantly be hearing the transmission jumping from gear to gear, but in my experiences with these new gearboxes, the shifts are so subtle that you almost have to pay close attention to notice the shifts in the numerically higher gears.

Fuel Economy
While most Ford Mustang buyers are far more concerned with performance than fuel economy, the automaker has to worry about fuel economy and this new 10-speed automatic transmissions should have a big positive impact over the 6-speed automatic. The trio of overdrive gears and the 7th gear with a 1-to-1 basis will all help to keep engine RPMs low when cruising down the highway, so especially when driving down the highway at high speeds – the 2018 Mustang should get better fuel economy numbers than the 2017 Mustang with the 6-speed auto.

Also, the gearing of this new 10-speed automatic transmission should lead to improved fuel economy at lower speeds as well, since the gears used to apply moderate power while driving around town are geared less aggressively than the 6-speed gears.

The bottom line is that after testing some other vehicles with 8- and 9-speed automatic transmissions, we can expect that the 10-speed in the 2018 Ford Mustang will make the car quicker and more efficient, but it will improve those parameters while shifting to subtly that the driver and passengers will hardly notice when the transmission moves between 7th and 10th gear.