Prepay Gas Option a Rip-Off at Most Rental Car Companies
Tuesday, 24 April 2012 | by Pat's Picks

USA Today did a little math and figured out that, at most rental car companies the “prepay for a full tank” gas option—supposedly your best deal—is more than the average nearby pump price. Enterprise was the exception. At nine out of 10 airports the paper studied, Enterprise’s prepay prices were cheaper than at nearby gas stations.
SOURCE: USA Today