Two Engines For The Price Of One

The New Infiniti QX50 Promises Both Power And Parsimony.

 

- Tim Ansell

Infiniti’s new luxury SUV has any number of high tech tricks up its sleeve yet its most significant lies tucked away under the bonnet, hidden out of view. The QX50 is the first production car in the world to be fitted with a variable compression turbocharged engine, a 2.0-litre, four-cylinder in line ‘VC Turbo’ unit which Infiniti claim has the advantage of delivering both increased power and greater economy, two parameters of engine performance usually diametrically opposed. They achieve this apparent marvel by varying the effective stroke length of the connecting rod through an ingenious cam mechanism, which reduces the stroke length and thus decreases the compression ratio when the driver demands power, but maximises the stroke length and thus the compression ratio when the engine is idling or under low load. If that doesn’t mean a great deal to you, don’t stress; in layman’s terms, Infiniti are promising sporty acceleration when required, greater economy when it’s not, so customers will no longer have to choose between a frugal four cylinder or a thirsty V6 — instead they can have the best of both worlds. The engine also weighs less than a V6, and generates lower levels of vibration, thus improving overall performance and comfort levels.