Horse Powertrain has revealed the HORSE B20, a 2.0-liter turbocharged four-cylinder hybrid engine rated IPX8 waterproof and able to operate at wading depths up to 3.6 feet (1.1 meters). Designed for HEV, PHEV, and REEV applications in off-road SUVs and pickup trucks, the HORSE B20 produces 188–248 hp (140–185 kW) and 221–280 lb-ft (300–380 Nm) of torque, according to the company. Horse Powertrain says the engine maintains continuous, stable power output under high-load off-road conditions, including 100% grade climbing.
Highlights
- IPX8 waterproof rating permits operation at depths up to 3.6 feet (1.1 meters)
- 188–248 hp (140–185 kW) and 221–280 lb-ft (300–380 Nm) from a 2.0-liter turbocharged, direct-injection four-cylinder
- 48.4% brake thermal efficiency via a Miller-cycle combustion strategy, the company reports
- 287 lb (130 kg) engine weight for HEV, PHEV, and REEV platforms
Engine Specifications and Combustion Design
The HORSE B20 is a four-cylinder, 2.0-liter inline gasoline engine with a turbocharger and direct injection. Horse Powertrain reports a brake thermal efficiency of 48.4%, enabled by a Miller-cycle combustion strategy.
Several in-cylinder features are aimed at leaner combustion and improved fuel economy and range:
- High-pressure injectors and high-tumble intake ports to improve air-fuel mixing
- Piston design that exploits the “squish” effect to promote mixing at the peak of the compression stroke, supporting faster, cleaner combustion at ignition
Outside the cylinders, the engine uses a gantry-type aluminum block with an integrated exhaust manifold and a simplified balance shaft system, which the company says improve NVH, durability, and efficiency. A variable displacement oil pump manages oil flow and pressure across operating conditions.
Thermal management relies on a fully active dual-cooling system intended to hold the engine at its target operating temperature during continuous slope climbing and extended high-temperature operation.
How Does the HORSE B20 Operate Underwater?
To reach the IPX8 rating, the HORSE B20 uses a fully sealed structure with torsional vibration dampers and dedicated engine-transmission sealing. Its electrical components and sensors are also IPX8-rated.
Those sensors continuously monitor the engine’s operating environment. When the engine is submerged, the control system automatically limits power or adjusts throttle response based on sensor feedback, which the company says keeps the engine running stably during deep wading.
Applications and Market Debut
Ingo Scholten, Deputy Chief Technology Officer of Horse Powertrain, said: “The HORSE B20 demonstrates how we are meeting the full range of market needs, delivering flexible engine and powertrain solutions designed for multiple use cases and applications. Supporting HEV, PHEV and REEV platforms, the HORSE B20 enables new opportunities across a range of vehicle categories – particularly off-road applications, due to the engine’s waterproofing and climbing capabilities. This engine is another step forward in advancing modern powertrain technology and a further example of how Horse Powertrain is pushing our industry forward.”
The engine was first shown at the Beijing Auto Show 2026, where Horse Powertrain also debuted its X-Range C15 Direct Drive hybrid system. The HORSE B20 has since entered service in a PHEV powertrain in the China-market Geely Galaxy Cruiser 700 off-road vehicle, paired with the HORSE 3DHT230 three-speed hybrid transmission.
The B20 joins a 2.0-liter lineup that includes the recently upgraded HORSE V20, which serves mild-hybrid and plug-in hybrid applications.
