Infiniti challenges traditional engine design

Variable compression turbocharged 4-cylinder engine to debut in Paris

Published: August 14, 2016, 4:55 PM
Updated: November 21, 2021, 3:25 PM

Infiniti VC-T engine

Infiniti has spent the best part of the last two decades working on the engine it will introduce at the 2016 Mondial de l’Automobile in Paris — a production ready variable compression turbocharged (VC-T) 4-cylinder engine.

Billing it as one of the most advanced engines the world has ever known, Infiniti says it’s a technological tour de force that will revolutionize internal combustion efficiency.

“VC-T technology is a step change for Infiniti. It is a revolutionary next-step in optimizing the efficiency of the internal combustion engine,” said Roland Krueger, president of Infiniti Motor Company. “This technological breakthrough delivers the power of a high-performance 2.0-litre turbo gasoline engine with a high level of efficiency at the same time.”

To date, engines have had fixed compression ratios (which dictates the amount of power the engine is able to put out). The compression ratio is the comparison to the volume of the cylinder chamber when the piston is at the bottom of its stroke to when it is at the top of its stroke. For example, if at the bottom of the stroke, the volume of air is 1 litre (900 cc in the cylinder plus 100 cc in the chamber) and at the top of the stroke it’s just the 100cc in the chamber, the ratio is 10:1.

The VC-T engine is able to seamlessly raise or lower the height of the piston stroke, thereby increasing or decreasing the amount of air drawn into the cylinders and raising or lowering the compression ratio. The engine control module applies the optimum ratio to the demand of the driving situation, varying the displacement of the engine and varying the compression ration between 8:1 (for higher performance) and 14:1 (for higher efficiency).

The benefits to the owner are reduced fuel consumption and emissions, and reduced noise and vibration levels. The engine is also lighter, which will also aid fuel economy, and it’s smaller (meaning it may also influence future exterior design trends).

More information on displacement and power figures will be available when it is introduced at the end of September.