Ford announced the opening of its order banks for the 2021 Mustang Mach-E electric SUV Wednesday. 

With that, Ford released adjusted power and torque specs for the Mach-E—reflecting a 3% to 4% boost in rated power over previous preliminary estimates. 

But in the electric car world, where Tesla acceleration videos have made us all a little numb to the meaning of traditional power and torque—yet hyper-aware of remaining charge—the prevailing wisdom is that range is the new horsepower. And so one other newly released spec for the Mach-E stands out: usable capacity. 

In both order guides for dealers and in the configuration and build pages for the Mach-E, Ford has started listing the usable capacity of the battery packs—68 kwh for the Standard Range Battery and 88 kwh for the Extended Range Battery—instead of the previously cited gross capacities of 75.7 and 98.7 kwh, respectively. 

Ford Mach-E Premium build configurations - July 2020

Ford Mach-E Premium build configurations - July 2020

It’s also modified those latter capacities to reflect actual installed capacity: 76.8 and 98.5 kwh, respectively.

“Ford is adjusting the way it communicates battery capacity to align with EPA and WLTP certification test cycles and to be more transparent about usable energy levels,” said company spokeswoman Emma Bergg. “The range for Mustang Mach-E was based on the usable battery capacity and therefore the estimated range figures do not change."

That’s an important shift for several reasons. Firstly, it underscores that Ford is potentially using less than 90% of the pack’s sum cell capacity, and leaving about 10% for battery degradation and longevity. It reassures that the Mach-E might still offer its original advertised capacity, or close to it, after six, eight, or possibly even ten years. 

2021 Ford Mustang Mach-E range warning

2021 Ford Mustang Mach-E range warning

Secondly, it highlights that the Mach-E is probably more efficient than earlier specs suggested. At 300 miles (or more) of EPA-rated range for the 88-kwh Extended Range, that’s better than 3.4 miles per kwh—not Tesla efficiency, but far better than the similarly sized Jaguar I-Pace (or anything larger than compact EVs from Hyundai, Kia, Chevy, or Nissan). 

To compare, Audi initially made 83.6 kwh (88%) of the E-Tron’s 95-kwh usable, but it’s since expanded that to 86.5 (91%), arriving in the U.S. in the 2021 E-Tron Sportback.  

Although Tesla hasn’t formally released usable capacity for its packs, it tends to use a significantly higher amount of the gross capacity—as much as 96 percent of the pack it used to list as 100 kwh, for instance. 

And that leads to an important final point. The Ford decision leaves an option open in the future to make the battery “bigger” without an expensive production change. If Ford decides that degradation is happening slowly enough, it could enable more of the battery’s capacity to be available—potentially via an over-the-air update. 

Ford hasn’t yet verified that kind of update might be possible, but it did reveal in May that nearly all parts of the Mach-E can receive OTA updates, “so your experience never stops improving.”

2021 Ford Mustang Mach-E

2021 Ford Mustang Mach-E

It’s already improved the rate of range it expects drivers to be able to recover in quick DC fast-charging stops at 150-kw connectors. In May Ford also said that the Mach-E will be able to recover up to 61 miles of range in just 10 minutes—about a 30% improvement over the 47 miles previously quoted.