GENERAL Motors and powertrain development partner Isuzu Motors are to launch the first 'common rail' direct injection four-valve diesel engine in a 4x4 this year. GM subsidiary Vauxhall and Isuzu will install the new engines in their Monterey and Trooper 4x4 models when restyled models go on sale in the summer.

The Monterey is currently powered by a 3.1-litre turbodiesel engine and a 3.2-litre petrol engine, but the new range of models will see the introduction of a 3.0-litre turbo diesel engine with 'common rail' direct injection which is claimed to produce best-in-class power and torque and a saving in fuel economy. There will also be a new 3.5-litre V6 petrol engine.

Both power units feature four-valve DOHC cylinder heads making the 1998 Monterey and Trooper the first recreational vehicles in the world with a diesel engine that combines four valves per cylinder with 'common rail' direct injection.