Speaking at Audi’s recent annual conference, he said engines with “electro-mechanical assistance for forced induction” and “variable compression ratios” were in development.
Hackenberg also said coasting would become an important fuel-saving technology over the next few years. A coasting function - where the transmission disengages from the engine on the overrun - is already built into some VW Group models equipped with dual-clutch automatic gearboxes.
Hackenberg gave no details on how Audi will introduce variable compression ratio technology, but the principle has long been something of a Holy Grail for engine designers. Being able to vary an engine’s compression ratio depending on the immediate demands being placed on it should lead to significant advances in efficiency.
In 2000, Saab demonstrated its experimental supercharged and turbocharged SVC engine, which used a tilting block to change the volume of the combustion chamber and, therefore, the compression ratio. More recent designs have altered compression ratios by changing the throw of the crankshaft or through the manipulation of conrods.