The government rates the fuel economy of flex-fuel vehicles at about 165% the miles per gallon (mpg) they would get on straight petrol.

ECONOMIST: Behind Detroit's sudden embrace of ethanol

Finally, a measure in the bill would require the administration to raise corporate average fuel economy (CAFE) standards from their current level of 25 miles per gallon (mpg) to 35 mpg by 2020.

FORBES: Magazine Article

They support a weaker proposal than the one put forth in the Senate's version of the energy bill, which would raise the standard from 25 miles per gallon to 35 mpg by 2020.

FORBES: Magazine Article

Under the new legislation, the fleetwide standard will be raised to an average of 35 miles per gallon by 2020, up from 25 mpg today.

FORBES: Magazine Article

First, it increases vehicle fuel efficiency to a fleetwide average of 35 miles per gallon by 2020, up from the current level of 25 mpg.

FORBES: Magazine Article

Fueleconomy.gov lists reports from 65 owners of the new Ford C-Max hybrid, who have together averaged 39.1 miles per gallon in combined city and highway driving not the 47 mpg that Ford advertises based on the performance the car recorded in the five-part fuel-economy test program required by the EPA. Among those drivers reporting, some achieved as much as 56 mpg, and others as few as 28 mpg.

WSJ: Why Your Mileage May Not Measure Up

Back then, lawmakers set the bar at 25 miles per gallon meaning an auto company's fleet of cars had to average 25 mpg.

NPR: Energy Law Leaves Out Wind, Solar Tax Credits