Fareed Zakaria's piece in Newsweek suggested that plug-in hybrids combined with flex-fuel engines could greatly reduce our dependence on petroleum. We've talked about plug-in hybrids before, so what's this about flex-fuels?
Broadly put, flex-fuel vehicles are those which can run on a variety of fuels, not just gasoline. While most gasoline engines will run acceptably on mixtures of a small amount of alternative fuel (e.g., ethanol) with gasoline, flex-fuel engines are designed to handle much greater amounts of non-petroleum fuel. "E85," or a mixture of 85% ethanol and 15% gasoline, is a flex-fuel choice with some automaker support. This article at the World Business Council for Sustainable Development provides an overview of non-petroleum fuel options; generally speaking, the ones which include "mixed" or "blended" forms in the description are suitable for flex-fuel use.
An advanced flexible engine technology, HCCI, offers a greater range than most flex-fuel engines. As we noted in August, Fiat will be introducing an HCCI engine design in Brazil able to use four different fuels -- gasoline, diesel, ethanol and natural gas. HCCI engines have significantly lower emissions and much greater efficiency than regular internal combustion engines, but they're also much trickier to design and maintain.
Comments (5)
Trivia: GM makes many flex-fuel E85 pickup trucks, but they do it to exploit a loophole in the fuel-efficiency laws (it reduces their fleet average, thus allowing them to make more big SUVs and crappy cars).
Posted by Mikhail Capone | March 7, 2005 3:04 PM
Posted on March 7, 2005 15:04
Trivia: GM makes many flex-fuel E85 pickup trucks, but they do it to exploit a loophole in the fuel-efficiency laws (it reduces their fleet average, thus allowing them to make more big SUVs and crappy cars).
Why would reducing the fleet average allow a company to make more fuel-inefficient vehicles?
Posted by Joseph Willemssen | March 7, 2005 3:14 PM
Posted on March 7, 2005 15:14
The MDI aircar which is allegedly close to production says on its website that its bi-fuel version (compressed air and fuel) will be capable of doing 2000 km between refills, which sounds pretty amazing - if slightly implausible. Does anybody know if this is correct? If it is, I want one!
http://www.theaircar.com/
Posted by Daniel Johnston | March 7, 2005 3:29 PM
Posted on March 7, 2005 15:29
Joseph: Oops, my mistake. I meant that it artificially *raises* their fleet average.
They count these huge pickups as "alternative fuel cars" because of the flex engines (that almost nobody uses, or even knows about because they aren't marketed that way -- not to mention the absence of E85 fuelling stations) and thus raise their fleet average, allowing them to produce more and bigger SUVs (where their real profit comes from) that they otherwise could because they wouldn't meat the EPA's required fleet average (which is a flawed way to do things in the first place).
It's all documented in the book "High & Mighty: The Dangerous Rise of the SUV".
Posted by Mikhail Capone | March 7, 2005 4:10 PM
Posted on March 7, 2005 16:10
Mikhail, I'm still not clear on this. It seems as if FFVs get lower mileage than their gas counterparts:
http://www.fueleconomy.gov/feg/compx2001f.jsp
Looking into it, it seems that "alternative fuel" vehicles are treated with a strange calculus which inflates their actual fuel mileage for CAFE consideration:
http://www.nhtsa.dot.gov/cars/rules/cafe/overview.htm
Now it makes more sense.
Posted by Joseph Willemssen | March 7, 2005 4:45 PM
Posted on March 7, 2005 16:45