Gas Engines Aren't Dead, They're Getting Smarter
The Death Of Combustion Can Wait
At the start of this decade, the electric-vehicle transition felt inevitable, spurring a race for survival among automakers. Several, including Volvo, planned to go all-electric as early as 2030. But policy and market changes have since helped bring combustion engines back into the game, particularly in the U.S., where hybrids have gained significant traction.
Despite this shift, automakers continue to develop combustion engines to make them more efficient and produce fewer emissions, goals that mirror the broader push toward EVs. Automotive News reported that more efficient engines are being made possible by advances in areas such as variable compression ratios, higher-pressure fuel injection, sophisticated valve control, cylinder deactivation, electric turbochargers, and electrically operated accessories.
As a result, engine thermal efficiency has reportedly risen from around 20% in 2000 to more than 40% in some modern Toyota and Nissan engines.
Horsepower Isn't The Only Number That Matters
Chinese automaker Geely, meanwhile, claims to have achieved 48.41% peak thermal efficiency with a 1.5-liter engine for hybrid vehicles. Under certain highway driving conditions, its i-HEV system reportedly returned around 105 mpg.
Major American players General Motors and Stellantis have also made new engine developments. GM designed the new 6.7-liter LS6 small-block V8 with improvements in thermal efficiency and output, increasing power from 495 hp in the outgoing LT2 to 535 hp. It will power the 2027 Chevrolet Corvette Stingray, Grand Sport, and Grand Sport X, while other LS6 versions will power the automaker's full-size pickups and SUVs.
Stellantis, meanwhile, boasts a highly efficient Hurricane 4 Turbo that produces 324 hp from 2.0 liters, or 162 hp per liter. It may not be as dramatic as the 1.6-liter V6 (produces 574 hp excluding the electric motors) in the Mercedes-AMG One, but the Stellantis power unit is still noteworthy given that it is designed for the mass market.
The Gas Engine Is Evolving
The report also touched on automakers increasingly using artificial intelligence to make combustion engines more efficient, including GM during the development of the aforementioned LS6.
It is difficult to predict how the automotive industry will evolve, as evidenced by the rapid changes of the past few years that have cost several automakers billions in EV-related write-downs. As it stands, some governments are delaying or softening their full-EV timelines. The EU's 2035 zero-emissions target, for example, is being revised to allow a limited continued role for combustion vehicles. This would give automakers more time to transition while preserving options for buyers unwilling to deal with range anxiety or charging constraints.
Perhaps the best-case scenario for enthusiasts is that automakers develop even more efficient engines, allowing combustion-powered cars to continue running alongside EVs.
Copyright 2026 The Arena Group, Inc. All Rights Reserved.