I once had a GoodIdea, at least I thought so. It was an idea that could add to the Quality Of Life. I would have liked to have acted on the idea, but I had neither resources, or position of power with which to institute it, so it did not become a reality then: About twenty years ago, I had a good idea which was based on the Diesel Electric Locomotive: That if one would scale this design down to operate an engine meant to propel an automobile, an enhanced scheme which also employ the use of storage batteries and would have two operating modes for the internal combustion engine: 1) at highest fuel-energy operating point, or 2) at idle or off. The excess of electricity generated above automotive needs would be routed to the partially discharged batteries. If the batteries were fully charged, the engine would go to idle (of off), and the electricity would then be supplied by the batteries until a certain state of discharge occurs. I thought it was a GoodIdea then, and I think it is still a GoodIdea! HybridAutomobiles are being produced, but the recognition that it would be a GoodThing is not yet realized at a high level of awareness and action, either by manufacturers, consumers, or government. The most effective and efficient engine may be something other than the typical piston driven, perhaps employing the turbine, or rotary types. -- DonaldNoyes ''You should look at the design of the Toyota Prius drive train. It basically does what you describe. It's engine even runs on a cycle that produces less peak power but burns the fuel more completely, resulting in fewer emissions. -- IanOsgood, proud Prius owner'' I may also become such an owner (but not yet). (Adding Efficiency to Utility) (I am the proud owner of a Blue Ford Explorer 1999 270,000 miles). What color is your Prius? -- DonaldNoyes ''Silver, the most popular car color. There are a number of hybrid SUV's coming to the market, if that is your preference. -- IanOsgood'' Car color popularity: * White - 19.3% * Silver - 18% * Black - 12.4% * Med. Dark Blue - 11.4% * Med. Dark Gray - 7.5% * Med. Red - 7.1% * Med. Dark Green - 6.7% * Light Brown - 5.1% * Bright Red - 4.5% * Gold - 1.8%