Mayflower has designs on your car

The internal combustion engine: More power for less fuel

British engineering firm Mayflower has unveiled a novel car engine that it claims can cut fuel use by 40% and slash exhaust fumes by half.

I have always felt that the conventional crank and con-rod was flawed

Dr Joe Ehrlich, Mayflower

The improved fuel economy has been produced by changing the way that pistons connect to the crankshaft in an engine.

Mayflower claims that its "intelligent" e3 engine could mean the advent of vehicles with adaptable engines that act like a nippy run-about in town, but become more saloon-like on the open road.

Mayflower said the engine could be in production within five years.

Flawed design

The e3 Variable Motion Engine is the fruit of 11 years of research by Mayflower scientist Dr Joe Ehrlich, who has spent his whole life working with internal combustion engines.

The Mayflower engine

In conventional engines, the piston is connected directly to the crankshaft of a car with a linkage called a con-rod. The crankshaft converts the up-down motion of the pistons into rotational motion to turn the car's wheels.

The e3 engine puts a pivot between the crankshaft and con-rod. This change means combustion is more complete because the piston slows down just after the fuel is ignited. Better combustion means more power per piston stroke and fewer unburnt fuel emissions.

"I have always felt that the conventional crank and con-rod was flawed," said Dr Ehrlich. "It wastes too much energy and does not optimise combustion."

The changed angle of the connecting con-rod at combustion imparts more of a kick to the crankshaft, making the engine more energy efficient. In conventional engines, some of the energy generated during combustion is wasted because the con-rod is directly over the crankshaft.

Dr Joe Ehrlich: Inventor of the e3 engine

The pivot sitting between crankshaft and con-rod is also the key to the e3's adaptability. By altering the angle of the pivot, the capacity, and therefore power, of the engine can be changed while it is running.

Mayflower claims that the engine could mean much greater fuel efficiency for a huge variety of vehicles. The engine of a truck could be changed to cope with a full load and then "downsized" as it returns empty to a depot or yard.

Because the e3 engine is based on existing engines, manufacturers should find it easy to work the design into their production lines, said Mayflower chief executive John Simpson.

Over 160 million combustion engines are made every year.