HORSE B20: Waterproof 2.0-Litre Engine Built for Extreme Off-Road Hybrids

HORSE Powertrain has revealed the HORSE B20, a four-cylinder, 2.0-litre turbocharged gasoline engine designed for HEV, PHEV, and REEV powertrain applications. The engine’s standout feature is its waterproofing: it is designed to meet IPX8 waterproofing requirements and operate at depths of up to 1.1 metres. HORSE Powertrain also states the B20 maintains continuous, stable power output under extreme off-road, high-load conditions, including 100% grade climbs, positioning it as a gasoline engine built for hybrid and range-extended powertrains in extreme off-road vehicles and deep-water wading scenarios.

What Is the HORSE B20?

The HORSE B20 is a four-cylinder, 2.0-litre inline turbocharged gasoline engine with direct injection, weighing 130kg. It is not itself a complete hybrid powertrain; rather, it is a combustion engine designed for integration into HEV, PHEV, and REEV powertrain applications.

The engine produces 140–185kW of power and 300–380Nm of torque, running on an advanced Miller cycle that HORSE Powertrain states achieves a brake thermal efficiency of 48.4%.

To support leaner, cleaner combustion, the HORSE B20 uses high-pressure injectors and high-tumble intake ports for improved air-fuel mixing. Pistons are designed around the “squish” effect, improving air-fuel mixing near peak compression for a cleaner, faster combustion event.

Waterproofing: Up to 1.1 Metres Under IPX8 Requirements

The HORSE B20 is designed to meet IPX8 waterproofing requirements and operate at depths of up to 1.1 metres while maintaining stable, uninterrupted performance.

To achieve this, the engine uses a fully sealed waterproof structure with torsional vibration dampers and dedicated engine-transmission sealing, along with IPX8-rated electrical components and sensors that monitor the surrounding operating environment. When the engine is submerged, the control system can make adjustments such as limiting power or adjusting throttle response, based on feedback from these sensors, to maintain stable operation under deep wading conditions.

100% Grade Climbing and High-Load Off-Road Capability

HORSE Powertrain states the B20 maintains continuous and consistent power output under extreme off-road, high-load conditions, including 100% grade climbs.

A fully active dual-cooling system helps keep the engine within its optimal operating temperature range during continuous slope climbing and long-duration, high-temperature scenarios. A gantry-type aluminium block with an integrated exhaust manifold, plus a simplified balance shaft system, contribute to improvements in NVH, durability, and overall efficiency. A variable displacement oil pump ensures optimal oil flow and pressure throughout the engine.

HEV, PHEV and REEV Applications

The HORSE B20 is designed for three electrified powertrain architectures: HEV, PHEV, and REEV. Ingo Scholten, Deputy Chief Technology Officer of HORSE Powertrain, said the engine “enables new opportunities across a range of vehicle categories,” pointing to off-road applications in particular due to its waterproofing and climbing capabilities.

Real-World Application: Geely Galaxy Cruiser 700

The HORSE B20 was first showcased at the Beijing Auto Show 2026. It has since been used within a PHEV powertrain in the Geely Galaxy Cruiser 700 off-road vehicle (China only), paired with a HORSE 3DHT230, a three-speed intelligent hybrid transmission.

HORSE Powertrain: Company Background

HORSE Powertrain describes itself as an independent powertrain technology leader, built on 125 years of heritage from Renault and Geely, operating 18 manufacturing plants and 5 R&D facilities across three continents, and offering ICE and hybrid powertrain solutions.

The company operates through two divisions. Horse Technologies, based in Madrid and rooted in Renault innovation, runs 8 plants and 3 R&D centers across Europe and South America. Aurobay Technologies, carrying the legacy of Geely and Volvo Cars, operates 10 plants and 2 R&D centers across Europe and Asia, out of Gothenburg and Hangzhou Bay.

HORSE B20 Key Specifications

Specification	HORSE B20
Engine type	Turbocharged gasoline engine with direct injection
Configuration	Four-cylinder inline
Displacement	2.0-litre
Weight	130 kg
Power	140–185 kW
Torque	300–380 Nm
Combustion cycle	Miller cycle
Brake thermal efficiency	48.4%
Applications	HEV, PHEV and REEV
Waterproofing	IPX8-compliant waterproof design
Maximum water depth	Up to 1.1 metres
Gradeability	100% grade
Cooling system	Fully active dual-cooling system

HORSE B20: Key Questions Answered

Source: 4256692.pdf Image credit: Horse Powertrain