If you had the choice, would you fill your car with gas that costs $3.59 or $2.99 a gallon? The truth is that sometimes, you get more for your money by paying extra at the pump.
The Denver Post discusses the prospect of filling up a vehicle with E85—which is 85% ethanol, 15% gasoline, and is significantly cheaper than standard gas. E85 isn’t widely available in Colorado, let alone other parts of the country. (This link lists locations with E85 pumps.)
But even if you have the option of filling up with E85, there are reasons not to. First, your car must have flexible fuel engines. Many vehicles do not, though a quick check of your owner’s manual will clue you in whether E85 is OK.
Second, a car full of E85 gets worse gas mileage than one pumped with regular gasoline. Fill your vehicle with E85, therefore, and you’re bound to need to fill up—and pay—to fill up more often. How often, and what, exactly, is the tradeoff in mpg? According to the Denver Post story:
Experts say flex-fuel vehicles using E85 lose anywhere from 10 percent to 30 percent in mileage compared with gasoline, depending on the vehicle model. The mileage gap has been narrowing as manufacturers improve the efficiency of the vehicles.
If you get 30% worse mileage with E85, then it only makes financial sense to choose E85 if it’s 30% cheaper than regular gasoline. At one gas station in the Denver area, E85 was $2.99 a gallon—or 17% cheaper than regular gas, running $3.59 per gallon.