It is a sensation. At least for people who are interested in the technology of a car. Infiniti introduces the first engine with a variable compression ratio. The compression ratio is actually always fixed. It results from the cubic capacity and piston travel and so far it could not be varied. There are research engines from other manufacturers (for example Audi), but Nissan's Nobel subsidiary is now introducing this groundbreaking novelty for the series. This puts Infiniti in the front row and presents an engine technology that could save the combustion engine for a few more years. Performance like a V6, consumption like a four-cylinder.
Six-cylinder power, four-cylinder thirst
The VC-T engine was recently presented by Infiniti's top engine developer, Shinichi Kiga-San. An engine in which 20 years of research work and over 300 patents have gone. The abbreviation VC-T stands for “variable compression” and for “turbo”. Because the engine can not only change the compression, and not between two values as with other “research engines”, but fully variable between 8: 1 and 14: 1. In addition, the VC-T will also have a turbocharger. Performance data are not yet known. But if Infiniti speaks of the performance values of a “Highpower 4 Cyl. Turbo engine”, then you will have to show at least 280PS, more like 300 PS. All of this should still achieve the consumption of a “super-efficient” four-cylinder. At diesel level? Do we expect 280 hp and 4.5 liters of fuel consumption? They also want to combine this with the smoothness and comfort of a V6 petrol engine. And that in an SUV? Because that is also an open secret, Infiniti will continue to expand its own SUV range and next on the agenda is a modern “mid-size SUV”. The right name? QX50?
This engine is a breakthrough for Infiniti. It makes you independent of the diesel engine, which you hardly like in the world and only really needs from us. Yet. The engine will combine the joy of turning and power of a modern turbo engine with the economy of a diesel. At least that's the view. And thus fits perfectly into the next generation of SUVs.
The seesaw makes it
In simplified terms, this is made possible by a rocker on the crankshaft. This rocker guides the connecting rod on one side and the adjustment mechanism of the “Harmonic Drive” is attached to the other side. While this rocker, called Multi-Link, sits on the crank shaft and transfers the force from the piston there, it is also variable in position. This changes the possible stroke of the piston and thus the compression ratio. Infinitely variable and individually controlled for each cylinder.
Low compression in the area of high performance requirements and high compression for maximum efficiency. In addition, a valve control was implemented to make the valve times on the inlet side variable. While the inlet side is controlled electronically, the outlet side receives hydraulic valve control. The engine is also able to switch continuously between an Atkinson combustion process and the classic four-stroke process.
Power, consumption, comfort - a new dimension?
Infiniti promises the power of a sporty high-end four-cylinder, the consumption of a diesel and the smoothness of a V6. For the head of the brand, Roland Krüger, it is clear: "The VC-T engine has what it takes to become a diesel replacement. And of course you can combine the VC-T technology with any displacement and any number of cylinders - even with hybrid technology. "
The engine will have its world premiere at the Paris Motor Show, we look forward to further insights. The new engine is to go into series production from 2018, making Infiniti the first manufacturer to use this technology.
