Saturday, August 7th, 2004

One common objection to steam car development is that gas/electric hybrid cars are the cars of the future because of their higher fuel efficiency in city driving, and that steam car developers are therefore "missing the boat" or bucking "the smart money".

The June 11th, 2004 issue of USA Today contains an article by James R. Healy reporting the following information:

The official EPA city fuel mileage estimate for the Honda Civic hybrid is 48 mpg. Yet Consumer Reports independently tested the same vehicle and got only 26 mpg in city driving. Many conventional gas cars, even some performance gas cars like Ford Mustangs, can equal or beat that fuel mileage in city driving. Similar results have been found with other hybrid cars. It has already been agreed, including by hybrid developers and manufacturers, that hybrids offer no fuel mileage improvement over comparable conventional gas cars in highway driving. But now they don't even offer better fuel mileage in city driving?

Healey (USA Today): "So many people have complained about the disappointing fuel economy of gas-electric hybrid cars that the federal government is telling automakers to consider putting more realistic mileage labels on their cars or do a better job warning buyers that they won't get the advertised mileage."

Note that the "advertised mileage" is the US federal government's own (EPA) fuel mileage figures.

EPA response: "the last thing we want to do is discourage further development and market penetration of this technology." (Chris Grundler, Deputy Director, EPA Office of Transportation and Technology).

Car industry response: "Potential reputation damage to the technology is a very valid point. We hope that doesn't come out of this." (Mike Michels, Toyota spokesman)

The USA Today article also notes that Toyota and Honda receive about $1500 per hybrid car in US federal government subsidies. No word on reported Japanese and other government subsidies for hybrid car research-and-development and production. One government belt-tightening, and those subsidies could disappear -- taking hybrid cars with them.

Hybrid cars, theoretically, should have much higher city fuel mileage than comparable conventional gas cars. I find it very disturbing to discover that this is not the case, especially after writing several articles on this website based on my assumption that the superior efficiency claims for hybrid cars are correct and accurate.

Why do gas/electric hybrid cars have only about the same real-world fuel mileage as conventional cars, even in city driving? In theory, they should have much higher fuel mileage. Then again, in theory, conventional gas cars "should" have much higher fuel mileage than steam cars. Yet under typical real-world road conditions, comparable steam and gas cars have about the same fuel consumption.

This reminds me of the old story about how a standard aeronautical engineering analysis of the wing area, muscular strength, weight, and aerodynamics of a bumblebee leads to the theoretical conclusion that bumblebees cannot fly. Yet we see them buzzing happily around all the time -- apparently bumblebees are not aeronautical engineers. :)

It also brings to mind the old saying: "Don't believe everything you read".

The big problem with theoretical estimates of automobile fuel consumption is that vehicle and road conditions and driving habits vary tremendously from one car to another and from one day to the next. This makes theoretically estimating fuel consumption, even with laboratory and other test data, a very complex job, with very uncertain results. It seems more worthwhile to rely on actual user-reported fuel consumption results.

Remember these facts next time somebody tells you that steam cars are a waste of time due to the superior efficiency & impending future dominance of gas/electric hybrid cars.