Mini’s engine boss has ruled out the possibility of introducing a diesel hybrid system, even though one of its key powerplant partners, PSA Peugeot Citroën, is ploughing ahead with the technology.
PSA jointly developed the Mini’s petrol motors with BMW — and its diesels were only recently replaced in the line-up by Munich-sourced engines.
But Wolfgang Kuttler, head of Mini diesel engines, told Autocar that the PSA Hybrid4 — due to appear on the DS4 and 508 — was “a very expensive and heavy system”.
He added, “It only brings fuel savings in town, not on the faster, more open roads commonly used in Europe. We’ll never use a system like it at Mini for that reason.”
According to Kuttler, Mini is focusing on improving economy in its diesel engines using other methods.
“I believe that we are currently getting about 50 per cent of the efficiency available in diesel engines,” he said.
“We intend to concentrate on improving ancillary drive, lowering internal friction, increasing injection pressure and optimising turbo response, among other aspects. Variable valve timing is a possibility but it’s low down on the priority list.”
BMW has already announced that it is working on a three-cylinder turbodiesel engine for the future, but Kuttler said this configuration will need a 1.5-litre capacity or more — “not only to keep the BMW and Mini performance values but also because it is not efficient to have an engine so short of power that it must be worked hard”.