First revealed at the Beijing Auto Show 2026, Horse Powertrain’s latest range extender (REEV) pairs a 2.0-litre turbocharged engine running on 100% methanol with a cutting-edge axial flux motor.
For workshop owners and technicians tracking the fast-moving shift toward alternative fuels and hybrid architectures, this latest release from Horse Powertrain offers a fascinating look at where range-extended electric vehicle (REEV) design is headed.
The new HORSE D20 Methanol system is a dedicated power unit designed to recharge an EV’s battery on the go, delivering up to 105kW.
Packing a combined weight of 170kg, the complete assembly merges a 2.0-litre turbocharged four-cylinder engine with power electronics and an advanced generator system.
Ultra-Lean Burns and Cold Starts at -35°CDesigning an internal combustion engine to burn 100% pure methanol comes with distinct combustion challenges, particularly when starting in cold conditions.
Horse Powertrain has tackled this by fitting the D20 with a 240mJ high-energy ignition system.
This setup allows the engine to run ultra-lean burns in the cylinder, boosting overall fuel economy, while guaranteeing reliable pure-methanol cold starts at temperatures as low as -35°C.
From an emissions standpoint, the D20 Methanol unit keeps $\text{NO}_x$ output to 35mg/kWh, aligning with China’s CN6b regulation and comfortably passing the Euro 7 threshold of 60mg/km.
For technicians, the most compelling element of the D20 setup isn’t just the fuel choice, it’s the physical generator architecture attached directly to the crankshaft.
Rather than using a conventional radial flux motor (where the rotor spins inside a cylinder-shaped stator), Horse Powertrain has chosen a yokeless axial flux design.
Here, components are stacked as disks, featuring two rotors sandwiching a single stator.
Axial flux generator gains
– 46% shorter profile compared to an equivalent radial flux motor, dramatically reducing overall powertrain length.
– 63% higher volumetric power density (kW/L), saving critical engine bay space.
– 96.4% peak electrical efficiency, aided by an embedded silicon carbide (SiC) power module that minimises electrical switching losses.
By pairing a lean-burn methanol combustion process with high-efficiency axial flux generation, the complete unit achieves an impressive 47% fuel-to-energy conversion ratio in laboratory testing.
In practical terms, the unit generates $1\text{ kWh}$ of usable electrical energy for roughly every $2.1\text{ kWh}$ of methanol consumed.
That means the HORSE D20 can fully top up a kWh EV battery using just 19.6 litres of fuel.
“The HORSE D20 Methanol is one of our boldest statements of intent so far,” said Fortune Zhao, CTO of Horse Powertrain.
“Along with reflecting our commitment to alternative fuels… the HORSE D20 Methanol is a staging ground for a range of cutting-edge technologies to deliver a powertrain of unparalleled compactness and efficiency.
“This can be seen in our use of an axial flux motor to achieve the necessary width and volumetric power density… marking one of the first uses of the technology in a mass-market automotive powertrain.”
