Ford Study Finds 36,000 Five-Year-Old Mach-Es Retain 92% Battery Capacity

Ford’s five-year battery report on approximately 36,000 Mustang Mach-E electric SUVs found that the vehicles retained 92% of their usable battery capacity on average. The 2021 models had covered an average of 55,000 miles over 5.2 years, giving Ford a fleet-scale view of battery aging rather than an isolated high-mileage example.

The company’s aggregated connected-vehicle data, current as of August 2026, covered 2021 model-year Mach-Es sold to retail and fleet customers in the United States and Canada. Collectively, the vehicles had traveled about two billion electric miles.

What 92% capacity means and what it does not

Usable capacity measures how much energy the battery can hold relative to its usable capacity when new. It is closely connected to driving range, but the two are not interchangeable. Weather, speed, tires, climate-control use and other operating conditions also affect how far an electric vehicle travels on a charge.

As a theoretical illustration, a top-trim 2021 Mach-E originally rated by the EPA for 305 miles would correspond to roughly 280 miles at 92% capacity under the same test conditions. That calculation helps put the percentage into practical terms, but it is not a new EPA rating or a guarantee of the distance an individual vehicle will cover.

The distribution around the average is also important. Ford reported that 95% of the roughly 36,000 vehicles registered battery health between 87% and 97%. That spread shows meaningful variation within the fleet while indicating that most packs remained within a relatively narrow 10-percentage-point band after five years.

Six-figure mileage produced a limited additional decline

Mileage alone did not produce a steep drop in the high-use groups. More than 2,000 Mach-Es with over 100,000 miles retained more than 91% of their usable battery capacity on average. That was only slightly below the 92% average for the full group, despite those vehicles having traveled nearly twice the cohort’s average mileage or more.

The sample becomes much smaller at the next threshold. More than 30 Mach-Es with over 200,000 miles averaged 88% battery health. These vehicles retained most of their usable capacity, but the limited group size makes the result less representative than the figures for the full fleet or the 100,000-mile group.

Ford’s results also broadly align with separate datasets using different samples and measurement methods. Recurrent reported that participating electric vehicles retained 95% of their original observed range after five years. Battery-testing company Aviloo found that most models in its 500,000-test dataset registered 90% to 94% battery health at approximately 93,000 miles, with the Mach-E at 92.5%.

The findings apply to one battery chemistry

Every Mach-E in Ford’s 2021 dataset used a nickel-cobalt-manganese battery pack. Ford did not begin offering lithium-iron-phosphate batteries in the Mach-E until the 2023 model year, so the five-year findings cannot yet describe how those newer packs will age over an equivalent period.

The chemistry distinction also affects charging guidance. Ford says frequent full charges generally are not needed for daily use with the nickel-cobalt-manganese packs studied here. Some newer lithium-iron-phosphate packs benefit from occasional charging to 100% so their battery-management systems remain calibrated.

Pack aging depends on more than accumulated mileage. High temperatures and regularly fast-charging to 100% before discharging close to empty can accelerate wear. Ford recommends Level 2 charging for routine use, sparing use of Level 3 DC fast charging, preconditioning while the vehicle remains plugged in and parking in shade during extreme heat when practical.

Before launching a vehicle, engineers physically test cells and use computer models to estimate degradation under different temperatures and charging profiles. Real vehicles then supply the long-duration feedback that accelerated laboratory programs cannot fully reproduce. Kevin Vander Laan, Ford’s technical leader for high-voltage battery cells and systems, described the process as “continuous learning,” with fleet data feeding back into battery management, owner guidance and future vehicle development.

The clearest boundary is time: these are five-year results for early Mach-Es, not a prediction of each pack’s ultimate service life. Still, the 100,000-mile group remaining above 91% on average and the smaller 200,000-mile group averaging 88% provides a substantial real-world checkpoint for the nickel-cobalt-manganese packs used in Ford’s first mass-produced modern electric vehicle.

By Robert McKinney — Editor-in-Chief for AMI’s automotive and mobility coverage, with a mechanical engineering background and a decade reporting on powertrain systems, EV innovation, and global vehicle manufacturing.