Horse Powertrain has developed a waterproof 2.0-litre turbo petrol engine aimed at hybrid SUVs and pick-up trucks that are expected to tackle deep water and steep terrain.
Called the Horse B20, the four-cylinder engine is designed for hybrid (HEV), plug-in hybrid (PHEV) and range-extended electric vehicle (REEV) applications.
Horse said the engine meets IPX8 waterproofing requirements and can continue operating when submerged in water up to 1.1 metres deep. It can also maintain power during a 100% gradient climb, equivalent to a 45-degree slope.
The 130kg engine produces between 140kW and 185kW, depending on application, with torque ranging from 300Nm to 380Nm.
Direct injection and turbocharging are used, while a Miller-cycle combustion process contributes to a claimed 48.4% brake thermal efficiency. Horse’s current technical page independently lists the same basic output figures and hybrid applications.
Waterproofing extends beyond the engine casing. Horse uses sealed engine-to-transmission connections, protected electrical components and sensors that monitor operating conditions.
If the engine is submerged, its control system can restrict power or alter throttle response to keep it running.
Cooling has also been developed with prolonged off-road use in mind. A dual-cooling system manages engine temperatures during extended climbing or operation in hot conditions, while a variable-displacement oil pump adjusts lubrication according to demand.
Other measures include high-pressure fuel injectors, high-tumble intake ports and specially shaped pistons intended to improve air-fuel mixing. The aluminium block incorporates the exhaust manifold, while a simplified balance-shaft arrangement is used to reduce vibration and weight.
The B20 was first shown at the 2026 Beijing Auto Show and has since been used as part of the plug-in hybrid system in the China-market Geely Galaxy Cruiser 700, paired with Horse’s three-speed 3DHT230 hybrid transmission.
Horse’s Beijing show material independently confirms the B20’s specifications and intended HEV, PHEV and REEV applications.
Horse deputy chief technology officer Ingo Scholten said the engine was developed to broaden the company’s hybrid powertrain applications, particularly for vehicles requiring greater off-road and wading ability.
