Sounds good, but is not correct. A car moving at a moderate walking speed is already past the limits of lamillar flow. Wind-tunnel experiments show than sometimes a sharply truncated back end works better than a taper, unless the taper is very long — too long for a car.
Cars on a highway are going much faster than birds.
Our 1996 VW Passat TDI (diesel) gets better mileage than most of these hybrids. Better diesels are on the way. It looks like European diesels will be up against Japanese hybrids in the mileage contest. I suspect that the diesels will win with superior muscle, leaving the hybrids for the crunchy crowd.
From an environmental standpoint, tghere are many problems with the hybrids when one considers the entire life-cycle from naufacturing to disposal. Think of the huge quantity of old batteries to be discarded somehow.
Diesel has about 11% more energy per unit quantity than gasoline. So yes, they should get better mileage with all other things being equal.
A barrel of crude oil produces about twice as much gasoline as it does diesel. Therefore as crude oil becomes more expensive gasoline will be less expensive per mile traveled than diesel.
Tell NASA that their curved pyramid tail over the rear engines of the shuttle doesn’t do any good. No, you’re WRONG, the suction on the square, flat back of a semitruck is aerodrag, no 2 ways about it. Next you’ll be saying that the aeroshells over cabs don’t do any good either.
For typical American drivers, diesels make much more sense than gasoline-electric hybrids.
A small, light car with a small diesel engine and a manual transmission can be very efficient.