Some diesels have been built with well over 100,000 psi fuel injectors. This is the reason why diesel fuel is so much more expensive than gasoline. Diesel injectors give diesels such good mileage that government couldn't make as much tax money if the price were lower. If we would apply this to gasoline engines, the gasoline would be atomized so much better, that we might get as much as 100 mpg. --- Why not a gasoline injector that is in the shape of a tiny engine valve. The pressure placed on the fuel by the pump, forces the tiny valve open, so that we get even pressure all the way around the valve. Control of the valve spring is what controls the amount of fuel. Better atomization from higher injector pressure is what mixes the fuel with the air better. Better mixing means better burn, means less fuel needed.