Transonic Combustion, based in Camarillo, CA, has developed a gasoline fuel injection system that can improve the efficiency of gasoline engines by 50 to 75 percent, beating the fuel economy of hybrid vehicles. A test vehicle the size and weight of a Toyota Prius (but without hybrid propulsion) showed 64 miles per gallon for highway driving. The company says the system can work with existing engines, and costs about as much as existing high-end fuel injection.