- The Horse B20 can operate in water up to 1.1 meters (3.6 feet) deep.
- It’s a 2.0-liter turbocharged four-cylinder engine that supports hybrids, plug-in hybrids, and range-extender EVs,
- In its highest state of tune, it produces 248 hp and 380 Nm (280 lb-ft).
- The B20 already powers the China-only Geely Galaxy Cruiser 700, a plug-in hybrid off-roader.
Hybrid powertrains are everywhere these days, but Renault and Geely are taking the technology a little further. Or, should we say, farther? Anyway, their Horse Powertrain joint venture has developed a new 2.0-liter turbocharged gasoline engine that keeps working even when the vehicle is wading through relatively deep water.
Carrying a BMW-esque B20 codename, the four-cylinder has an IPX8 rating and can operate at depths of up to 1.1 meters (3.6 feet). That's considerably more water than most people will ever want to drive through, although serious off-roaders routinely face situations where the limitations of a conventional powertrain can become a concern. According to Horse, the new engine can also maintain stable power delivery in demanding off-road conditions, including climbing grades as steep as 100 percent.
The B20 isn't just about surviving deep water, either. It's designed from the outset for electrified powertrains, supporting conventional hybrids, plug-in hybrids, and even range-extender EVs. Depending on the application, the 2.0-liter turbocharged engine produces between 188 and 248 horsepower, while torque ranges from 300 to 380 Newton-meters (221 to 280 pound-feet).
Okay, But How Did They Waterproof An Engine?
Horse sealed the engine's structure and added dedicated sealing between the engine and transmission. The electrical components and sensors are also rated for IPX8 operation. Sensors monitor surrounding conditions, and when the engine detects submersion, the control system can automatically adjust power output and throttle response.
A fully active dual-cooling system also keeps temperatures under control during prolonged high-load operation, such as climbing steep slopes for extended periods. A variable-displacement oil pump optimizes oil flow and pressure depending on operating conditions. The engine itself uses an aluminum block with an integrated exhaust manifold, while a simplified balance-shaft system is intended to improve noise, vibration, and harshness, as well as durability.
It's A High-Efficiency Gas Engine
At 130 kilograms (287 pounds), it's also reasonably light for what it is. Horse uses direct injection, a Miller-cycle combustion process, and a claimed brake thermal efficiency of 48.4 percent. High-pressure injectors, high-tumble intake ports, and specially designed pistons are intended to improve combustion efficiency and, ultimately, fuel economy.
That matters because this isn't supposed to be a thirsty old-school off-road engine. The B20 is designed to work as part of an electrified powertrain, where electric motors and a battery pack can complement the gasoline engine.
Just to be clear, Horse isn't simply claiming its engine can survive getting wet. The company has engineered the B20 around the idea that deep-water crossings and extreme off-roading are part of the job.
It Already Powers A Production Vehicle
It's already part of the plug-in hybrid powertrain in the Geely Galaxy Cruiser 700, a China-only off-road vehicle we recently covered.
That's perhaps the most interesting part of the announcement. Rather than being a curiosity built to generate headlines, the B20 is already being integrated into an actual off-road vehicle.
Geely Galaxy Cruiser 700
Motor1's Take: As impressive as the B20’s ability to operate underwater is, there’s an obvious downside to all this engineering: complexity. Waterproofing an engine, adding sensors and control systems, and integrating it into a hybrid powertrain means more things can go wrong. Then again, modern cars are becoming increasingly complex, whether they're hybrids or EVs.
Horse is betting that the benefits of combining a waterproof combustion engine with electrification outweigh the potential drawbacks. It’s an interesting solution to a very specific problem, but we’d still be curious to see how the B20 holds up after years of mud, water crossings, and hard use. Because making an engine survive 1.1 meters of water is one thing; making all that extra hardware reliable for the long haul is another.
