It seems that the current spate of environmental consciousness encircling the globe has spawned a number of entrepreneurs wanting to cash in on the need to go greener - including legitimate operations like Tesla and its electric cars, as well as some more dodgy operations such as the proponents of hydrogen boosting. The latest company to be promoting clean technology is EcoMotors International, a group that has plans to introduce a five-seater car capable of achieving 100mpg by next year - and with claims like that we may be tempted to throw them into the same lump as the hydrogen boosters, save for the fact that the man behind the company has some very impressive credentials.

EcoMotors is run by Professor Peter Hofbauer, who worked for Volkswagen Group for two decades developing VW and Audi diesel engines. Now, the Professor has come up with a new engine design that retains the basic principles of internal combustion, but vastly improves the power density. Power density refers to a combination of factors such as weight, size, material costs, friction, fuel efficiency, emissions and heat rejection, and by improving one or all of these attributes we can improve the power density of an engine.

According to Hofbauer, a new opposed-piston opposed-cylinder (OPOC) engine design that he has come up with is 30% lighter, one-quarter the size and achieves 50% better fuel economy compared to today's state-of-the-art conventional turbo-diesel engines. Of course, such a bold claim will invite skepticism, and Hofbauer explains how the engine works on the EcoMotors website ( Apparently, the engine operates on the twin-cycle principle, generating one power stroke per crank revolution per cylinder. It comprises two opposing cylinders per module, with a crankshaft between them, and each cylinder has two pistons moving in opposite directions. This innovative design configuration eliminates the cylinder-head and valve-train components of conventional engines, offering an efficient, compact and simple core engine structure. The result is an engine family that is claimed to be lighter, more efficient and economical, with lower exhaust emissions compared with conventional designs.

Hofbauer has also developed an electronically controlled turbocharger that he claims effectively eliminates turbo lag because the electric motor provides much faster turbine response, and also provides boost when there is low energy from the exhaust flow.

Whether or not the claims are plausible remains to be tested by independent bodies, but if Hofbauer's engine design lives up to the hype then it will be interesting to see how this technology could contribute to future cars.