Infiniti have confirmed that their variable-compression engine first announced in 2016 at the Paris Auto Show is now production-ready. This makes it the worlds first to go from the research and development stage to actual production.

 

Looks incredibly simple from this diagram, apparently looks can be deceiving.

Designed, as the name suggests to have a variable-compression ratio, the ‘VC-Turbo’ as it’s being marketed by Infiniti, has been labelled to have the power of a V6 petrol engine, with the efficiency and torque of a diesel equivalent.

 

The engine is able to offer any compression ratio between 8:1 (typical for high performance engines) and 14:1 (used by many manufacturers for high efficiency). It is able to change the compression ratio’s on the fly, based on input from the driver, and throttle response.

The red and green lines indicate the difference in height of the piston when at Top Dead Centre, thus the differing compression ratio.

The four-cylinder, 2.0 Litre, VC Turbo is being touted to have lower noise, vibration, and emissions than a conventional internal combustion engine, and lighter and more compact than a V6 with similar output. 

The efficiency, reduction in noise and vibration (which is inherent with four-cylinder engines), will be what wins the engine the prestige and place on the world stage that Infiniti are chasing.

Will the VC-Turbo outperform a diesel in torque and efficiency? Infiniti believe it will, but I think we’ll have to wait for it to hit the real world market and real world conditions to see.