A new engine that could make cars up to 50 percent more efficient has been described as "promising technology" by Bill Gates, and is now set to power its first vehicle thanks to an investment from the billionaire founder of Microsoft.
The $23.5 million (€18.6 million) investment, which was made jointly by Gates and Sun Microsystems co-founder Vinod Khosla, is enough to complete the engineering and testing of the OPOC engine, which is produced by Detroit firm EcoMotors.
The engine represents a less dramatic approach to the problems of green automotive technology, relying on considerable improvements to the combustion engine rather than the introduction of new technology such as electric or hydrogen powertrains.
EcoMotors says that the new engine architecture, which uses two cylinders, each with two opposed pistons, delivers up to 50 percent greater fuel efficiency with a corresponding reduction in greenhouse gas emissions.
It's also half the size and half the weight of conventional one-piston-per-cylinder engines, making it far less expensive to produce.
As the two pistons, running in opposing directions, only have to travel half the distance from the cylinder that a traditional piston would do, the engine is more efficient and can be run at higher speeds.
This year, the firm plans to complete a prototype 100mpg passenger car based on the OPOC engine to convince the world that its technology is viable, although with its management team, EcoMotors already has a good case.
The firm is led by former General Motors executive Don Runkle and the OPOC engine is the brainchild of Volkswagen's former head of powertrain development Peter Hofbauer, the man behind the Clean Diesel engine used in the Volkswagen Jetta.
“The OPOC engine can be an important step in providing affordable, low-emission transportation for the developing world,” said Gates.
“EcoMotors has developed a promising technology that could help reduce levels of greenhouse gas emissions in a low-cost, globally relevant way.”
Gates' investment in green automotive technology echoes that of Elon Musk, the millionaire co-founder of Paypal who invested heavily in EV maker Tesla Motors before becoming its CEO in 2008.