Renault-Geely JV's Horse B20 engine runs underwater and beats the Toyota Prius on efficiency

Horse Powertrain, the engine joint venture between Renault and Geely, has unveiled a 2.0-liter turbocharged gasoline unit designed for hybrids that can keep running while fully submerged. Christened Horse B20, it carries an IPX8 certification and is rated for crossings in water up to 1.1 meters deep — exceeding even the diesel Land Rover Defender's 90 cm wading capability.

Submersion is made possible by a sealed structure with torsional vibration dampers and dedicated sealing between the engine and transmission, while electronic sensors monitor conditions in real time. Once deep water is detected, the control module limits output and remaps throttle response to avoid failures and keep the vehicle stable through the crossing. Geely also claims the Galaxy Cruiser 700, the model that debuts the engine, can float for up to two hours.

Efficiency is the other headline: running a Miller cycle, the B20 reaches 48.4% thermal efficiency, surpassing the roughly 40% of the Toyota Prius hybrid engine that has served as the civilian-market benchmark. The 130-kg unit delivers 190-251 hp and 30.6-38.7 kgfm of torque via high-pressure direct injection, high-tumble intake ports and mixture-optimized pistons, while an aluminum block with an integrated exhaust manifold and dual active cooling lets it sustain climbs of up to 100% grade (45 degrees).

First shown at the Beijing auto show, the B20 has launched in China under the hood of the Galaxy Cruiser 700, an all-wheel-drive plug-in hybrid SUV positioned against the Defender, paired with the three-speed 3DHT230 intelligent transmission. Horse Powertrain says the design serves HEV, PHEV and range-extender platforms, and the venture can also supply it to other manufacturers.