Anyone who remembers two-stroke motorbike engines belching an oily blue fog will be amazed to learn that Lotus sees this kind of engine as a clean solution for the future.
The Norfolk-based company insists that the Omnivore engine on display at the Geneva motor show could be a way to reduce the emissions of petrol engines without the need for reduced capacity and expensive additions such as turbochargers.
'The fuel in those old two-stroke engines often needed lubricating with oil, and they also had carburettors rather than fuel injection, with the result that you would get oil and unburned fuel coming out of the exhaust,' a company insider told us.
The Lotus engine has direct fuel injection to get round this and is designed to ensure oil stays in the sump rather than entering the engine's combustion chambers.
Lotus points out that four-stroke engines are 'an automotive peculiarity' and that marine transport, right up to the largest supertanker, relies on two-stroke.
'No-one can claim they are not durable because people are not going to buy something that could get them stranded out at sea,' our source said.
'We would not have embarked on this if we did not believe there was a good chance we could produce an engine that has better emissions than what we have today.'
Omnivore is a single-cylinder research project partially funded by the Government. The next stage will be to produce a detailed technical paper, which Lotus is obliged to do within a year, to decide whether to progress further.