Drive a Diesel, costs less and get's better milage than a hybrid without all the extra parts to break.
And you can easily make fuel from vegetable oil. How's that for being "environmentally-correct"?
Yes. OTOH there could be something to be said for a hybrid diesel. In principle a diesel is simply a gasoline engine modified to the extreme for fuel economy over drivability, noise, first cost - indeed all other considerations (except durability; the diesel takes such a beating, and it so expensive anyway, that it has to be made durable in order to hold together at all - let alone last long enough for its fuel economy to overbalance its high first cost). The hybrid concept could readily compensate for the operability problems associated with diesels.In fact, there exists a diesel design which is even more efficient than the standard fuel-injected version, but is entirely inoperable in a standard vehicle with a mechanical transmission. The dual-fuel diesel has injectors for diesel oil, but that is intended only to act as a pilot charge, analogous to the spark plug in a gasoline engine. The main fuel source for the dual-fuel diesel is natural gas (gasoline would presumably work), carburated lean enough to prevent autoignition without the pilot charge of injected oil.
That system is highly efficient, but it is inoperable in a normal setup because the only way of controling its power level is to impose the load on it which will hold its RPM down to the desired speed which gives the desired power. As a practical matter that rules out the use of a mechanical transmission, but an electric drive can accomplish it.
I have no idea how that would play into emissions considerations, but otherwise it would seem to be a go - if indeed you are willing to pay for the most efficient drive short of a fuel cell. I would agree with the idea bruited by the GM exec who said that a city transit bus - which racks up high mileage in stop-and-go operation - is the least illogical application for hybrid technology.
VW TDI = 55mpg@60K miles
Went to look at a VW Jetta with diesel power - found the same bad economics as with hybrids. People have driven the price $2500 beyond the same care with a gas engine. I would have to drive a lot of miles to get back my $2500.