Infiniti creates history with variable compression engine
The first engine with variable compression ratio will go on sale in 2018 and you might be surprised to hear that Infiniti is the company behind this new chapter in engine technology.
Ready to make its debut at this year’s Paris Motor Show, the 2.0-litre VC-T engine will, according to Infiniti, promise “diesel economy with V6 power and smoothness”. Sources involved in the project say this VC-T powerplant is cheaper to manufacture than the Euro 6 diesel engine.
Power rating for this new engine is around 201kW and 390Nm but the biggest improvement comes from efficiency – a claimed 27% better than a petrol unit sans variable compression technology. These outputs will effectively make the current 3.5-litre V6 (a fairly mundane engine anyway) obsolete.
In selected markets the new 2.0-litre VC-T variable compression engine is destined for the yet-to-be-launched Infiniti GX80 while closer to home in South Africa, our first sample of this engine could take place behind the wheel of the Q30 or QX30.
Variable compression will alter the ratio from 8.1:1 or prioritise efficiency with a ratio of 14.1:1. This is done by a mechanical actuator arm that is connected to the piston’s conrods through a slot in the side of the engine block. By making the conrods in two halves, the actuator arm (connected to links in the conrods) can ultimately alter their length. A longer conrod gives high compression while a shorter length (usually fitted to turbo cars) drops compression. Other innovations include two parallel fuel injection systems; one sprayed directly into the combustion chambers and the other into the intake manifold.
A high compression ratio of 14.1:1 will require high octane fuel, the likes of which is not readily available in South Africa. It remains to be seen if Infiniti can bring their variable compression engine to developing markets.
