For now we can see how successful Toyota Prius as a green machine invention launched to market. Toyota introduced environmentally friendly machines. That’s sound good for everyone, it has a proven market too for them. They are rolling out their steps to a green and earth friendly machines.
The competition of manufacturers in making green cars will take the results. Will it mean that someday there's going to be a hybrid machine or green car in every home? Big manufacturers are building facilities to manufacture hybrid system microchips and batteries. However, it take time for consumers all over the world to use that hybrid cars as neither stopgap nor luxury, but reasonably priced, and in reach of everyone.
For now, only some people are able to pay for a more fuel-efficient engine that gives them better performance and also hopefully saves the planet. It is proven that those engines uses less fuel than the most efficient diesel machine and emits much fewer carcinogens into the atmosphere. However, those machine still need improvement for their performance and finally their lower price too.