Called the Concept-cX, which stands for compact crossover, this small 4x4 is intended to "create a link between Mitsubishi's passenger cars and SUVs."Under the bonnet lies an all-new 1.8-litre four-cylinder "Clean Diesel" engine – the first oil-burner Mitsubishi has developed. The engine uses a variable-geometry turbocharger and the latest diesel particulate filters to maximise efficiency and minimise emissions. It will meet forthcoming Euro 5 emissions regulations.In the Concept-cX, which will be revealed in the metal at September's Frankfurt motor show, the new engine comes mated to a dual-clutch gearbox from the new Lancer and a four-wheel drive system derived from the Outlander's.The Concept-cX is smaller than you'd think, at just 4.1m long – that's somewhere between a Focus and Fiesta - and uses interior plastics derived from plants, not oil. There's a split rear tailgate, and a high SUV-style driving position.Mitsubishi won't say whether or not the Concept-cX could make it to the road, but given the pressure on car makers to build smaller, more efficient cars, we wouldn't bet against it.In the meantime, the new engine will be used in the new Lancer hatch and saloon, out early in 2008.