[Big Dave]

Did you ever bother to think there might be a reason for "well, we've always done it this way" or "it's not worth the bother of changing". Do you think hundreds of thousands of engineers and managers over the years are complete blockheads?

Gas turbine engines have a huge problem, regardless of nominal efficiency. Throttle them down and they still guzzle fuel at a rate very near that used at rated power. Jet engines fuel burn at idle is about 80% of that at rated output. One of the arguments for three engine airliners was that they could taxi on the center engine with the wing engines shut off until they got near the end of the taxiway. Considering the taxi times at some airports at some times this is not a small consideration.

A gas turbine to run a Metro would be in the 20-25 kwh range. It would have to be in a series hybrid layout, charging batteries that move the car. The turbine would run in short bursts charging up the battery and then shutting off.

The Metro was a volume car, sold at a low price. How much of an increase in MPG would be required to offset a huge increase in vehicle price? I fear that is what GM is running into with the Volt. A $50,000 commuter car will be as difficult to sell as a $40,000 pickup if not worse.

There is a saying in the auto industry: “Any knucklehead could build a Ferrari or Porsche if money were no object. It takes a genius to build a Model T or VW Beetle that makes money.” Like the VW prototype that gets 200+ MPG. Nice, but it costs $100,000. Is that worth the price of changing?