Last year's energy bill increasingly requires a ten percent mix of ethanol in regular gasoline.

NPR: Ethanol-Based Fuel Enthusiasts Face Lack of Pumps

Diesels can save you hundreds of dollars each year in fuel costs, even though diesel typically costs more than regular gasoline.

WSJ: Car Advice: Is Going Diesel Worth It?��Me & My Car

But even those who want to sell E85 face problems just getting it to the pump, because there isn't a distribution system in place for ethanol like there is for regular gasoline.

NPR: Ethanol-Based Fuel Enthusiasts Face Lack of Pumps

Regular gasoline has an octane rating of 85-87.

FORBES: How to Build a Car that Gets 54.5 MPG

The lowest tax on regular gasoline?

FORBES: State Gas Tax Guzzlers