In my opinion rail should go all electric at least for the long range freight and passenger. Milwaukee did it so did Great Northern (only in Stevens pass was it??)
Trucks are now going hybrid. Eaton has a package that Kenworth and International are installing. Dunn Lumber has a 31,000GVW KW.
IF you are the "average? (??) American driver EV only will satisfy your daily driving needs with a range of 50 mile or so.
IF you are a contractor sales etc and drive all over then you will need hybrid. Choices and setup will depend on your driving needs. Seattle Portalnd will more than likely need a power plant large enough to drive the motor circa 30 to 50 HP. Prius would be your best bet for now and next year - after that ??
Around King County 30 or 40 miles you could get away with a 5 Kw unit especially so in stop n go. Could trailer mount it and not tow when not needed. Dan Bentler
May 13, 2009 Rating
Have you seen the Hybrid Trains in Japan and Europe by: Jerry
In 2007 the Japanese added a Hybrid engine to their train lines. It saves about 20% fuel and 50% less emission. The ones in Europe made by Bombardier in Canada and CS electric do even better. see an article and picture here.
May 07, 2009 Rating
Have you looked at the XR-3? by: Rich
It's a parallel hybrid (not like the series hybrid you're suggesting), but your idea reminded me of the XR-3 hybrid here:
http://www.rqriley.com/xr3.htm
Riley's plans call for a small diesel engine up front, with a separate electric drivetrain in the rear. I believe that he specified a small Kubota 3 cylinder engine.
Once again, a slightly different idea, but he has some cool plans on his site that might give you some inspiration.