Nissan VC Turbo engine uses variable compression ratio system

Nissan will unveil its variable compression ratio system engine, the VC Turbo, at the Los Angeles auto show next week. Reuters photo by Lucy Nicholson.

VC Turbo engine doubles thermal efficiency of current gasoline engines

Nissan Motor Co. will unveil its VC Turbo engine, which uses an efficiency-boosting variable compression ratio system, at the Los Angeles auto show next week.

Shinichi Kiga, the head of Nissan’s gasoline engine project group, told Reuters that the global automaker plans to keep improving the internal combustion engine and that the VC Turbo engine is part of that vision.

On Nov. 28, Nissan will unveil its Infiniti QX50 sport utility vehicle at the LA Auto Show. The luxury SUV engine uses the variable compression ratio system which will boost thermal efficiency to about 40 per cent, as much as twice the level of current gasoline engines available.

Thermal efficiency is the power an engine generates from a unit of fuel. Kiga says his goal is to develop engines for Infiniti and Nissan vehicles that offer thermal efficiency of 50 per cent.

The VC Turbo engine could prove to be a challenge for policy makers looking to encourage the use of electric vehicles.

James Chao, Asia-Pacific chief of consultancy at IHS Markit Automotive told Reuters that advancing ICE technology is “one of the most overlooked trends in the industry.”

He added “These advances beg the question…Are EVs the best solution to the issue of vehicle greenhouse emissions?”

The Infiniti QX50 VC-Turbo. Infiniti image.

The new Nissan engine uses electronics and software to choose an optimal compression ratio for combustion. This results in an average of 30 to 35 per cent higher fuel economy than the 3.5 V6 engine it replaces.

The VC Turbo has comparable power and torque to the old engine and Nissan says the VC Turbo matches a diesel engine for torque. Matching the torque of a diesel engine has been a long-time struggle for gasoline powered engines.

Kiga told Reuters that along with higher power and better fuel efficiency, the VC Turbo system costs thousands of dollars less than a comparable gasoline-electric hybrid car.

He said Nissan may offer a VC Turbo hybrid in the future.

Toyota is also working to develop more efficient gasoline engines. It has developed a 2.4 litre, four-cylinder engine for its latest Camry sedan with a maximum thermal efficiency of 40 per cent.

Toyota says it has developed this technology without using technologies like variable compression, but by incrementally improving its existing technologies.