China beats Toyota at its own hybrid car game with 48% gas engine efficiency record

China is going gaga over vehicles it calls EREVs (for Extended Range EVs) that combine the best of the electric vehicle and ICE powertrains with breathtaking total range numbers.

This trend has sparked a renewed investment in hybrid powertrains, and the new Mach 1.5T gas engine of Dongfeng has managed to beat both Toyota and the record holder BYD in terms of thermal efficiency.

This specification shows how well the ICE unit converts the energy derived from burned fuel into actual work of its moving parts and usually ranges from just 20% to about 40%. Toyota's gas engine in the Prius is very well made and returns a thermal efficiency rating close to the top range, while the world's biggest EV maker, BYD, has hybrid powertrains with very high 46% ICE efficiency, too.

The most efficient gas engine for hybrids

Dongfeng was one of the early hybrid vehicle proponents in China and has now managed to develop the Mach 1.5T as the most frugal engine that will go into mass-market hybrid vehicles with over a 48% thermal efficiency rating. The ICE has gotten the "Energy Efficiency Star" certification from the China Automotive Technology and Research Center (CATARC) that is responsible for testing such claims.

The automaker managed to hit the exceptional efficiency both by the usual methods of increased compression ratio and faster combustion, as well as by introducing innovations like coating the cylinder bore with thermal spray and integrating the oil pump.

The combustion optimizations affect the turbocharger with variable geometry and the electric VVT system, as the hybrid engine has no valve seats. The result is an ICE that works at its highest 48% efficiency rating over half of the time it's operational and returns a 10% range increase from an already extremely frugal unit.

It remains to be seen if the Chinese brands will overdo hybrid vehicle production capacity as they did with purely electric vehicles, but meanwhile, good things like the Mach 1.5T engine will be happening. Dongfeng recently unveiled a trim with innovative AWD hub motor system that removes the need for CV joints and even brakes, making the vehicle lighter and more responsive.

The hybrid vehicles coming out of China are being equipped with ever-growing battery capacities, too, with CATL unveiling dedicated packs that border on the size of pure electric EVs. This allows for extended range both in the city and on the highway, but apparently work on ICE thermal efficiency hasn't stopped, either.