I was talking to Alan Cicconi of AC Propulsion a couple of years ago. He's not sure that hybrid cars are at the present time such a big advantage over conventional cars. He says if you made a lightweight car with a small gasline engine, aerodynamic streamlining and high pressure tires you could easily match the mileage of the Japanese hybrids (which in truth don't get the mileage advertised anyway).
The Honda Insight is a 2-seater that weighed about 1600 lbs when it was introduced. The Honda Civic Hybrid is designed to appeal to more drivers because it is more similar to a regular Civic. I don't know much about the Toyota Prius except that it did not have much power when it was introduced.
The 2004 Honda Civic Hybrid (Continuous variable transmission) is supposed to get 47 mpg city, 48 mpg highway.
It has a 1339 cc engine and 93 horsepower (at 5700 rpm) and 13 hp from the electric motor.
It weighs 2749 lbs and starts just under $20,000.
In comparison, the 2004 regular 4-speed automatic Civic LX (mid-level Civic) is supposed to get 29 mpg city, 38 mpg highway.
It has a 1668 cc engine and 115 hp at 6100 rpm.
It weighs 2606 lbs, starts around $16,000, and has the same size tires and very similar body.
Several years ago, during the 1995-2000 body design, Honda offered a Civic HX, which had a continuous-variable transmission (CVT). It got 43 mpg highway, compared with 35 mpg highway for a 4-speed automatic transmission, which had a 1590 cc engine with 106 hp, and weighed about 1500 lbs.
The CVT probably contributes to the increased highway gas mileage in the current Civic Hybrid more than the hybrid technology does.
Simple math shows that a few hybrid compact cars on the roads will not noticeably offset the gas mileage for heavier or inefficient cars.
For 100 city miles, a hybrid (47mpg) uses 2 gallons, while an Excursion or Escalade (12mpg) uses 8; overall for the two, you get 20 mpg, not the numerical average of their mpg's; but, there aren't as many hybrids compact cars as there are heavier trucks, and there never will be, because the compact cars are not as versatile.
Given the higher price of the hybrid cars, the marginal gas improvement, the shorter lifetime, and the environmental pollution from batteries, hybrid cars don't seem ideal at this time.
The overall gas mileage of the nation would improve significantly by improving traffic flow (or reducing jams). This requires that transportation money be spent on freeways instead of mass transit.
Interesting stuff, gasline. Hard to find.