Stellantis Secures Patent for Three-Speed EV Gearbox

Stellantis (FCA US, LLC) has officially been granted a U.S. patent for a newly developed three-speed gear reducer for electric drive modules (EDMs), opening the door to smarter, more capable EV drivetrains across its brands. The patent on the United States Patent and Trademark Office (USPTO), filed on October 25, 2023, and granted May 1, 2025, outlines a compact but powerful solution aimed at delivering both off-road grunt and highway efficiency—two performance goals often at odds in today’s single-speed electric vehicle (EV) designs.

Rethinking the EV Transmission – 

The majority of electric vehicles on the market use a simple single-speed reduction gearbox. It works well for instant torque and smooth delivery, but doesn’t provide much flexibility. That’s where Stellantis’ new patent changes the game. It introduces a multi-speed solution using two planetary gearsets and four strategically placed clutches—two brake-type and two friction-type—to create three distinct gear ratios within a single electric drive unit.

The design is clever but not overly complex. It connects directly to the output shaft of the electric motor and can be configured to drive either the front or rear axle. Here’s how the gears work:

• 1st Gear (Low Range / 2-LO or 4-LO): Uses the third clutch to tie the motor directly to the sun gear of the first planetary gearset, while the first clutch locks the carrier to the housing. This slows output speed and boosts torque—ideal for towing, crawling over rocks, deep snow, or sand.
• 2nd Gear (High Range / 2-HI or 4-HI): Switches things up by locking the sun gear to the housing (via the second clutch) and sending torque through the carrier using the fourth clutch. This gives a higher gear ratio more suitable for normal driving conditions.
• 3rd Gear (Direct Drive): Both the sun gear and carrier are locked directly to the electric motor’s output shaft using the third and fourth clutches. This effectively bypasses the reduction, giving a 1:1 ratio for maximum efficiency at highway speeds.

These three modes enable the vehicle to operate within the motor’s optimal range, enhancing range and performance across various terrains and speeds. Better yet, shifting between the second and third gears can be done automatically and seamlessly, thanks to power-shifting capability. No more sudden drops in torque or jarring transitions.

Built for the Real World – 

What sets this patent apart from previous ideas is its practicality. It’s not just a concept for the track or a moonshot for next-gen exotics. Stellantis clearly engineered this to fit right into mainstream EVs—everything from Ram pickup trucks and Jeep® SUVs to performance Dodge EVs and Chrysler family haulers.

For off-roaders, this means EVs can finally achieve true low-range gearing without needing to install oversized motors or complicated dual-motor setups. That first gear setting—essentially 4-LO—gives the kind of stump-pulling torque drivers expect from gas or diesel 4x4s.

On the other hand, the third gear mode keeps the motor in its most efficient RPM range during highway cruising, helping to improve real-world range and reduce battery drain, which is crucial for long-distance travel.

Built-In Differential Support – 

The system is also smart about the final drive and axle output. The second planetary carrier drives a final gearset that can be coupled to a differential, either open or locking, mechanical or electronic. That makes this gearbox ideal for EVs that demand sophisticated drivetrain control. Whether it’s rock crawling with a locker engaged or modulating traction in wet conditions, the design makes sure you’re never stuck with just one drivetrain behavior.

Looking Ahead – 

While Stellantis hasn’t announced what vehicle will debut with this new three-speed gearbox, it’s safe to speculate. Ram’s upcoming electric trucks, Jeep’s electrified off-roaders, and Dodge’s new-generation muscle cars could all benefit from the flexibility this system offers. With its compact design, it could even scale into smaller crossovers or all-wheel-drive (AWD) EV platforms.

Most importantly, this patent shows Stellantis is serious about bringing back the flexibility and driving enjoyment of traditional multi-speed drivetrains, without sacrificing the benefits of electric power.

As the EV space matures, performance, range, and capability will no longer be trade-offs. Thanks to breakthroughs like this gearbox, drivers may soon get the best of all worlds—torque for trails, efficiency for highways, and seamless shifting without a drop of power.

Source: USPTO