Infiniti will unveil gasoline engine that matches diesel for power and economy.

INFINITI VC-T: The world’s first production-ready variable compression ratio engine

Infiniti will officially reveal the powerplant on September 29 at the 2016 Paris Motor Show. This engine, which is the world’s first production-ready variable compression ratio engine, has been in the development for 20 years and is a complete breakthrough in internal-combustion powertrain technology.


VC-T technology signifies a new chapter in the story of the internal combustion engine – engines are no longer limited by a fixed compression ratio.  The new powerplant uses two sets of connecting rods with a multi-link "pivot" in the middle to infinitely vary the compression ratio between 8:1 and 14:1. An electrically operated control arm changes the position of the multi-link, which changes the height the piston rises in the cylinder by as much as 5 mm. The crankshaft is relocated from the bottom of the engine to the middle.

VC-T technology delivers multiple customer benefits including significantly reduced fuel consumption and emissions, greatly reduced noise and vibration levels; it is also lighter and more compact than comparable conventional engines.

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

The technology gives the engine the performance of turbocharged gasoline engines while matching the power and fuel economy of today's diesel and hybrid powertrains - a level of performance and efficiency the conventional gasoline engine has so far struggled to achieve.

The turbocharged, 2.0-liter, four-cylinder VC-T engine averages 27 percent better fuel economy than the 3.5-liter V-6 engine it replaces, with comparable power and torque.

The new engine matches the diesel engine in torque - the amount of thrust that helps determine the car's acceleration.

The engine is also cheaper than today's advanced turbocharged diesel engines, Infiniti engineers said at the briefing at the company's technical and design center in Atsugi, south of Tokyo. They said it should also meet nitrogen oxide and other emissions rules in certain markets without requiring costly treatment systems.


"We think the VC-T engine could replace or become an alternative to some of today's advanced diesel engines," Tanuma said, noting the new engine's fuel economy and performance could be significantly boosted by coupling it to a gasoline-electric hybrid system, an option Infiniti said it is considering.

The technology will appear first in a 2.0-liter transverse-mounted turbocharged four-cylinder Infiniti QX50 in the 2017 calendar year/2018 model year. It will be mated to a CVT transmission. Both port and direct fuel injection will be used, and Infiniti lists a 27 percent improvement in fuel economy over their outgoing conventional-combustion V6.

The hinged connecting rods smooth out engine operation enough to allow engineers to remove the second-order balance shafts -- engine vibration and noise is said to be similar to that of a V6. While the first variable compression application will be a transverse inline-four, they are working on other applications.

The new variable-compression engine doesn't spell the end of the V6 at Infiniti, however. Indeed, the new VR30DDTT twin-turbo V6 engine will be offered in two different tunes, making either 300 or 400 hp when it debuts in the next QX80.

Infiniti also plans to add more performance to the luxury/performance equation by offering sportier versions of its vehicles, which will get an “S” on the deck lid, indicating the performance potential of each model.

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