Why Ford Put An F-150 Lightning Motor In The New 2024 Mustang Mach-E

The Ford Mustang Mach-E is an important model for the Blue Oval. It might not be the showiest, fastest, or shiniest vehicle out there, but it’s helping the brand gain a foothold in the EV world. To that end, it’s been iterating on the design and making improvements, and Munro Live is here to show us those in greater detail—in particular, the new rear motor.

At Munro Live, our host for the teardown is Paul Turnbull. He’s laid out an older 2021 Mustang Mach-E motor on the bench, and put it next to a rear motor sourced from the Ford F-150 Lightning. Why? Because it’s functionally the same in-house built unit as Ford is now using in the Mustang Mach-E.

Ford is now claiming faster acceleration and better quarter-mile times for the 2024 model—something dearly demanded by performance-focused customers. The teardown gives us a nice insight into why the new motor is the hotter sauce, particularly for the drag strip.

The Change

The decision to switch up the Mustang Mach-E’s rear motor didn’t make a lot of headlines, though Design News was across it earlier this year. Basically, Ford wanted to abandon the unit it was sourcing from an external supplier, and instead kit the model out with something developed in house. Hence, it ended up with the Lightning motor.

But what of the older part? The Mach-E’s original rear motor was manufactured by Borg-Warner. The example seen here was sourced from Munro’s 2021 Mach-E teardown.

It’s worth noting that for this analysis, we’re not looking at the rear drive unit as a whole. Instead, Turnbull is showing us a comparison between the stators of the old and new motors. That’s enough to illustrate the primary differences between the two.

Before we go further, let’s have a quick interlude to define some terms that are relevant to these permanent magnet motors—and I’ll throw in some diagrams below! What’s a stator? Well, it’s the big metal part of the motor that is, as the name implies, stationary. A stator is typically made of laminated plates of special steel that reduces eddy current losses, and is the structure that holds the windings. The stator windings are basically coils of copper wire wrapped around the stator core to generate the rotating magnetic field that makes the motor spin. If you’ve ever wound a coil of wire around a nail to make an electromagnet, you’re familiar with the concept. Windings in EV motors tend to use more advanced geometries and thicker wires, but the concept is the same. Wrap a conductor around some metal, run some current through it, and you’re generating a magnetic field.

What we don’t see in this video is the rotor, which is the central spinning part of the motor. The rotor has permanent magnets on it, so when the changing currents in the windings create a rotating magnetic field, the rotor spins in turn. It’s the job of the motor’s control electronics to energize and de-energize the separate windings in the right sequence to make the rotor spin. There are usually three sets of windings, or “phases,” that have to be switched in the right order to make the motor turn.

Okay, so back to the motors. The most obvious change to the new unit?  “In this case, though, Ford has decided to go with a winding that’s a little different,” says Turnbull of Ford’s in-house motor design. The new unit has an edge in some respects, but we’re not talking night-and-day here. “They’re making connections to both the inside and the outside layers [of the windings],” says Turnbull. “There’s a total of four connections made with each of the three phases.” To what end? “That gives us something we call four parallel paths,” explains Turnbull. “That enables a little more current flow capability.” In comparison, the older motor had just two current paths to each winding.

There’s a more obvious change though, which becomes apparent when the camera pulls back. The Ford motor is quite a bit longer than the Borg Warner unit. This is because increasing the number of parallel paths tends to decrease the torque output of the motor (assuming no other limiting factors) —but there’s a way to make up for that. “In order to get the same torque, they had to increase the stack length for this,” says Turnbull. “That also again gives the motor great thermal capacity, and so that’s going to be an enabler for holding on to that torque a little longer to give them the quarter mile times they’re looking for.” Basically, with more “thermal mass,” the motor can run at high output for longer.

Ford’s winding layout could offer another side-benefit, too. “This winding bears very interesting similarity to the Hyundai winding, and Hyundai’s system is at 800 volts,” Turnbull explains. “All Hyundai has done is take the same winding and put in double the number of turns and go two parallel paths instead of four.” Basically, Turnbull reckons the new design could be easily reconfigured for an 800-volt setup instead of the current Mach-E’s 400-volt architecture. “This leaves Ford an option, an easy upgrade path, to get to 800 volts with this same winding configuration, and it’s just a slight difference in how they connect it up here.”

Turnbull also points out the welds that hold together the Borg Warner stator, which is assembled from a stack of laminated steel plates. It’s a typical technique to hold the stator together, but it does introduce some inefficiency due to its impact on eddy current losses. Basically, it’s ideal if the individual stator plates are isolated from each other, as this keeps eddy currents induced in the stator smaller. However, the weld effectively acts as a current path between the laminated stator plates and increases these losses. In contrast, Ford’s stator plates are simply bonded together adhesively and there is no big weld creating a current path for a large eddy current. It’s worth noting, though, that in both cases, there are bolts going through the stator stacks when fully assembled anyway.

To What End?

In any case, the new unit appears to outperform the old one quite handily. For the 2023 model year, the Mustang Mach-E GT put out 600 pound-feet of torque, or 634 pound-feet in the GT Performance Edition (GTPE) models. For 2024, the basic GT does the same 600 pound-feet, but it can be specced with the “Performance Upgrade” which boosts that to 700 pound-feet. Mighty!

While power remains the same at 480 hp, straight-line performance is improved with the new motor. In the GT models, zero-to-60 mph takes just 3.3 seconds in the top trim, down from 3.5 seconds in the former GTPE model. It’ll now do the quarter-mile in just 11.8 seconds, down from 12.4 seconds previously. That may very well be possible because the new motor is able to run flat-out for longer thanks to its greater thermal mass… or it could all be down to the added torque. Most likely, it’s a combination of both factors.

It’s worth noting that this wasn’t Ford just going off on a tangent on its own. Customers had long been questioning the Mach-E’s drag strip performance, particularly given curiously low trap speeds in some early runs by customers who shared their time slips on forums. One poster noted their top speed in the GTPE model was lower than some lesser trims, suggesting the motor was leaving performance on the table in the top end. Ford was well aware of this, too. “We heard, ‘we want better performance, and we definitely want a better quarter-mile time,'” Mach-E chief engineer Donna Dickson told Design News earlier this year. The new motor may quell some of those concerns given the 2024 model is dropping those faster drag-strip times.

Beyond that, there’s also the simple benefit of sharing parts across models, with Turnbull noting the motor is shared with the F-150 Lightning. There are, naturally, obvious cost savings to be had in scale by using the same motor across two models. Notably though, getting the truck motor to fit the Mach-E wasn’t easy. “It was pretty difficult, putting it in after we launched,” Dickson told Design News. It is a different shape and fitting it into our package with the subframe was difficult.”

It’s always interesting to see the changes that effect a car’s performance, particularly when they’re so physically evident. Munro Live gives us a great look under the hood, under the frunk… just about under every weird bit of these modern EVs. The truth remains that you can best understand a complicated system by pulling it down to its component parts.

Image credits: Munro Live via YouTube screenshot, Ford