RE: The green engine; how about an engine that is in love with the environment
Well, I wouldn't agree that this engine is green yet. The chief product of any combustion and of most concern is carbon-dioxide.
Carbon-dioxide is a greenhouse gas and is able to trap heat emitted by our planet making global warming on the rise. As a result of this, I will opt for the renewable sources instead.
Although, it is not that renewable source "saints". However, their adverse effect on the ecosystem is mostly negligible.