Horse Powertrain Shows Off Its Compact, Cool Range-Extending Tech

With the world tapping the brakes on battery-electric vehicles (BEVs), Renault and Chinese automaking giant Geely decided it wouldn't be a bad idea to team up and start exploring some alternative powertrain options. Established in 2024, the new joint venture is called Horse Powertrain Limited, and its primary mission thus far has been to develop internal-combustion, range-extending engines and hybrid systems. Horse Powertrain's efforts are already bearing fruit, and it used Munich's IAA 2025 to showcase its new advancements, which we've outlined below. For more on what Horse Powertrain is up to and what it's planning, be sure to check the gallery for two company slides showing the breadth of their program pipeline of gas and hybrid engines and transmission offerings.

Horse Powertrain C15: Briefcase Range-Extender

The centerpiece of the Horse Powertrain booth was a tiny, 1.5-liter inline four-cylinder engine (above) with an oil scavenging system that can be set up to allow it to run vertically, horizontally, or at any angle in between. Measuring just 19.7 x 21.7 x 10.8 inches, it produces 94 hp in naturally aspirated form—perfect for C-segment or smaller vehicles, or it can be turbocharged to produce 161 hp to support D-segment or light-commercial vehicles. Even more impressive, those dimensions include the generator, inverter, exhaust, and cooling package. Sounds like it would fit in the frunk of a dedicated EV, no?

Developed to meet SULEV20, Euro 7, and China 7 emissions standards, the Horse Powertrain C15 range extender is also tuned to run on gasoline, ethanol and methanol flex fuels, and synthetic fuels in an effort to minimize arguments against its adoption. Along those lines, mass and cost have not yet been disclosed.

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Future Hybrid System

First shown in Shanghai (but we missed it there), this all-in-one system transforms an existing combustion or BEV vehicle into an HEV or PHEV. As such, it includes a similar 1.5-liter inline four-cylinder engine, transmission, motor, and power electronics into a single system. It’s available with one motor located between the engine and transmission, or two, with the second mounted to the transmission output shaft. The lower powered “ultra compact” variant measures 25.6 inches wide, the second 29.1 inches. Output of the ultra compact version hasn’t been disclosed, but the two-motor variant tops out at 349 hp and 380 lb-ft.

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Amorphous Iron Stator

The stator is the part of an electric motor through which all the electricity flows. Electricity flowing through copper windings induces a magnetic field in the steel holding the copper. This is never a cast piece. It’s typically formed by a stack of steel plates measuring 0.20 to 0.25 millimeters thick. Horse Powertrain has devised a method of making them 0.02mm thick(!). Who cares? Don’t you just need a ton more of them then? Yes, you do, but the electric current induced in the stator body flows around within each of these plates, resulting in eddy-current losses and increased heat. The thinner the plates, the lower the losses and heat.

And that’s not all—Horse Powertrain’s skinny plates are made of amorphous steel (or “metallic glass”), with a non-crystalline, disordered atomic structure that results in significantly lower iron losses and higher magnetic permeability—both great for efficiency. Horse claims its Amorphous Motor reduces iron losses by over 50 percent, achieving a claimed best-in-automotive motor efficiency of 98.2 percent. These benefits have been well known, but developing a commercial manufacturing process has been the holdup. Horse says it’s found a viable process of heating the steel to extreme temperatures, then cooling it very quickly.

GaN High Efficiency Generator

Horse Powertrain has found that by using a gallium-nitride power module, which enables ultra-high-speed switching capabilities and superior thermal performance (relative to traditional silicon chips), it is able to shrink the width of the generator in its range-extender. Superior heat dissipation also helps it operate over a temperature range spanning -40 to 230 degrees F. The generator can produce 67 hp at 4,500 rpm at a clamed 95-percent efficiency.

Small motors with higher efficiency and a super-efficient generator. Here’s hoping these cool technologies arrive in the USA someday. We’ll be watching for them to appear first on a Volvo or Polestar (our only current Geely or Renault products).