Bill Gates, chairman and co-founder of Microsoft Corp., has invested in EcoMotors International, a company that is developing encironmental friendly car-engine technology. Gates and Sun Microsystems co-founder Vinod Khosla have jointly invested $23.5 million into Detroit-based firm to help them complete engineering and testing of their Opoc-engine. The Opoc engine technology uses a twin-opposed cylinder layout and claims to make vehicles up to 50% more efficient. The firm wants to produce a car later on in 2010 that will return over 100mpg. Rumours suggest that a design for a motorcycle is also in progress. Gates said: “EcoMotors has developed a promising technology that could help reduce levels of greenhouse gas emissions in a low-cost, globally relevant way.”