Video: Ethanol gets worse mileage
posted at 2:30 pm on June 24, 2008 by Ed Morrissey
Most people who read Hot Air already know this, but this still surprises drivers. WPTY in Memphis reports on its own research on the effects of ethanol blends in contemporary cars, and catches some drivers at the pump reacting to the fact that they’ll pay more for less energy:
Supporters of ethanol use say it’s a cheaper, cleaner burning fuel. They claim the 10% blend has virtually no impact on fuel efficiency, but some mechanics disagree.
“It’s about 4-5% based on the numbers,” says Mark Block, owner of Block Automotive in Cordova.
Block says it’s simple science. He says a car must burn more ethanol to create the same energy as gasoline. So if you remove 10% pure gasoline and replace it with ethanol, the fuel won’t burn the same.
It’s not quite as simple as WPTY puts it, but it’s close. Ethanol contains about two-thirds of the potential energy of gasoline, which means one has to use about 50% more to get the same power as gas. Blending more ethanol into gasoline makes it less efficient, which means cars have to burn more of the blend than with straight gas to drive the same distance under the same conditions.
This doesn’t account for the varying efficiencies of ethanol varieties, either. Corn ethanol only produces a 2:1 ratio of potential energy to energy required to produce it, and transportation is much less efficient than with gasoline. Subsidies for farmers and rising food prices make corn ethanol more costly than ever. Cane-sugar ethanol can be grown cheaply and has an 8:1 return on production energy, but the US puts trade tariffs on cane-sugar ethanol while subsidizing corn farmers.
Democrats like Barack Obama like to say we can’t drill our way out of an energy crisis, but we certainly can do that, especially in the short term. What the rapid increase in food prices shows us, based on corn shortages, is that we cannot grow our way out of the energy crisis. We need realistic alternatives, not expensive and inefficient replacements that we can’t produce in amounts anywhere near impact levels. Anyone who says differently has their own power shortage.