In case you haven't heard, Flex Fuel technology is really starting to take off in the U.S., becoming more popular in late-model vehicles than technicians may realize. If you haven't had any training on these vehicles, you may find some of the technical changes OEMs have made to the engines will alter the way you diagnose fuel-related problems.

For those of you who are not familiar with this engine technology, a "Flex Fuel" vehicle is one that has been modified at the factory to allow it to operate on a mixture of alcohol and gasoline. The vehicle's modifications are not only likened to hardware differences in the fuel system, but there are also software differences in the PCM.

Are You Talking about Gasohol?
The alcohol of choice to use in a blended fuel is ethanol. Ethanol is made from distilled sugar cane, fermented corn and other such agricultural goods. You may have seen gas pumps that say "E85" on the sides of them. The "E" stands for "ethanol" and the "85" is the percentage of ethanol in the mixture (85% ethanol and 15% gasoline); E100 of course being pure ethanol.

You might also be familiar with the term "gasohol." Technically speaking, E85 is not really gasohol. Yes, the idea is similar, but the mixture makes the difference. Gasohol was the name given to some E10 to E15 fuels in the early 1980s. In gasohol, the primary ingredient was gasoline, and alcohol was the additive. However in E85, gasoline is ...