Vauxhall’s next generation Vectra will be one of the first General Motors’ products to use a new high-performance V6 diesel engine, being developed with Italian diesel specialists, V M Motori.

Bob Lutz, GM’s global product development vice chairman, confirmed the 2.9-litre unit at the New York motor show last month.

He says: “This will be a state of the art engine which can be used for front, rear and all-wheel-drive configurations. It should become a production reality within two years.”

It is particularly important to Saab and Cadillac. They are restricted currently to the 1.9-litre, 4-cylinder CDTi diesel engines with a maximum 150bhp output.

Lutz also revealed that dual-mode hybrid powertrain systems, being developed jointly with BMW and DaimlerChrysler, should provide up to 30% in fuel consumption savings. But he admits the premium per car price depends on how much manufacturers will subsidise the greener technology for “good PR”.

The hybrid system involves two electric motors integrated “seamlessly” into the automatic transmission and should debut in the second half of next year.

Despite GM’s commitment to the project, Lutz says buying a hybrid “on everyday fuel economy grounds is the dumbest decision in the world.”