Stuff with a Motor

The Prius Deception – Part III

If you had the patience to make it through my first two posts on this topic here and here, you know that I’m on a rant about why the US public isn’t better informed about alternative fuel technologies and vehicles that reduce our dependence on fossil fuels. Gasoline/electric hybrids, the only well-known semi-alternative to pure gasoline use today, represent a great technology that is being over-hyped and is being applied far beyond its optimal usage. Diesel fuel (including biodiesel) and E85 (85% ethanol) combined with electric motors and variable displacement engines (shutting down some of the cylinders when the demand on the engine is low) offer far superior fuel economy; most often with better performance than today’s hybrids. The kicker is that while few people know about it, most of this technology is available today.

To celebrate Earth Day, AutoWeek Magazine, did a road test of a variety of cars to test gas mileage over long distances. Some of the competitors in this test were the usual suspects in such tests – the Toyota Prius and the Honda Accord Hybrid – but AutoWeek also threw in a couple of non-standard competitors for the fuel-economy throne – the Chevrolet Corvette and the Jeep Commander. The results are interesting:



EPA Rating

Actual MPG

Gallons Used

Chevy Corvette


27.0 MPG

27.3 MPG


Honda Accord Hybrid


34.0 MPG

33.9 MPG


Jeep Commander


18.0 MPG

17.2 MPG


Toyota Prius


51.0 MPG

42.0 MPG


VW Jetta TDI


42.0 MPG

49.9 MPG


Note: the course was 349 miles of open road

First and foremost, the diesel blows everything else away. Not only does it go further on less fuel, it’s a bigger, faster and more comfortable car than the Prius, the second best in the test and the standard-bearer for high mileage vehicles and hybrid technology. In this case, the performance is actually better than is noted, because the Jetta was using biodiesel – a blend of diesel fuel and old Fryolater waste. The 7.0 gallons of fuel consumed is not 7.0 gallons of black gold, 20% of it came from vegetable oil used to cook yesterday’s french fries. See my post on why new diesel fuel is not your father’s diesel fuel any more.

The other interesting point is that the Corvette, one of the fastest cars on the planet, gets pretty good gas mileage when driven like you’d drive your Prius – i.e. like your grandmother drives. Now granted, the difference between the Corvette;s 27 MPG and the Prius’ 42 MPG is huge, but I don’t think the average person would believe that a high performance car like a Corvette could get almost 30 MPG.

Finally, the AutoWeek data shows off, once again, how distorted the EPA mileage numbers for the Prius are. The EPA rating of 51.0 MPG isn’t even close to the 42.0 MPG observed in the test. This test was also conducted on an early spring day in Michigan – I doubt the air conditioner was on. Current gasoline/electric hybrids take a tremendous hit in mileage when using accessories like the air conditioning. On a hot summer day, the mileage would be considerably worse.

The exciting thing about these results is that they point to some huge opportunities in the short term in reducing our consumption of fossil fuels. Diesel and E85 powered vehicles are already available and deliver solutions that decrease oil consumption well ahead of that delivered by current gasoline/electric hybrid technology. When combined with variable displacement and electric motors (creating diesel/electric and E85/electric hybrids) we can make a serious dent in the amount of oil imported into this country.

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