Infiniti just introduced a breakthrough new engine - and it doesn't have anything to do with electric cars

The Paris Motor Show was a showcase for sexy cars and exciting new concepts. But while all that was going on, Infiniti revealed a breakthrough new engine technology.

It's called the VC-Turbo, and it's important.

The world is busy these days thinking about an electric-car future, but the vast majority of the vehicles on the road are powered by internal combustion engines and will be for decades.

And before you start thinking that IC engines are yesterday's dirty tech, don't forget that automakers have been continuously innovating them for a century. They no longer belch plumes of black smoke, and in many cases, automakers have been able to extract impressive MPGs from them. Ironically, with all the extra weight that modern safety and technology features are adding to vehicles, fuel-economy from efficient IC motors has gone down.

So car companies are working hard to claw back good gas mileage, in large part because they're up against more stringent government fuel-economy and environmental regulations.

The new VC-Turbo is a great example on how much innovation is underway. In a statement, Infiniti said the 2.0-liter, four-cylinder power plant "promises to be one of the most advanced internal-combustion engines ever created."

The VC stands for "variable compression," and it means that the new motor can modulate its compression ratio to optimize its performance. According to Infiniti, it combines the torque of a diesel motor with a high-performance gas engine - minus the emissions problems that small-displacement diesels confront.

The CVT of turbos

Infiniti

The VC-Turbo could wind up in Infiniti's newest vehicles.

The VC-Turbo is to engines what a continuously variable transmission is to shifting gears: It can locate the ideal compression ratio for a given driving condition. Infiniti has been working on the technology for 20 years and thinks it will enable the automaker to offer better performance with a four-cylinder motor, replacing six-cylinder power plants.

CVTs are somewhat controversial - auto enthusiasts don't much like them. But they do serve up superior gas mileage. The VC-Turbo isn't likely to incur similar complaints because it could solve a problem with turbocharged engines: the "lag" between hitting the accelerator and the power coming on. This issue has long been seen as a compromise that just has to be dealt with if you want turbo advantages. But automakers have been getting better and solving the turbo problem.

The VC-Turbo will go under the hoods of Infiniti vehicles in 2018.