Learn & Understand

Fuel From the Field: Ethanol and the Food-vs-Fuel Debate

Ethanol — alcohol distilled from crops like corn and sugarcane — is blended into much of the world's gasoline as a renewable fuel grown from the land. But turning food crops into fuel raises hard questions, and ethanol's lower energy content means a tank of it carries you less far, complicating the case for growing what we burn.

Alcohol as Fuel

Ethanol is the same alcohol found in drinks, produced by fermenting the sugars in crops. It burns cleanly and can be mixed with or substituted for gasoline, offering a renewable, home-grown fuel that reduces reliance on imported oil. Blends of ethanol and gasoline power a large share of the vehicle fleet, and high-ethanol blends run in specially built flex-fuel cars.

The Energy Penalty

Ethanol has a catch: it contains noticeably less energy per unit than gasoline. A vehicle running on a high-ethanol blend therefore travels fewer miles on a tank, since each gallon delivers less energy to the engine. This means ethanol's often-lower price at the pump does not automatically translate into cheaper driving — the reduced range must be weighed against the savings.

Food Versus Fuel

The deepest debate around ethanol is ethical and economic: growing crops for fuel uses farmland, water, and grain that could feed people. Diverting food crops into fuel tanks can raise food prices and strain resources, prompting criticism that the world should not burn its food. Whether biofuels are wise depends heavily on what is grown, where, and at what cost to the food supply.

The Promise of Better Biofuels

Researchers pursue biofuels that sidestep the food conflict — made from crop wastes, inedible plants, or algae rather than food grain. These “advanced” biofuels aim to keep the renewable benefit while avoiding the food-versus-fuel dilemma. Ethanol remains a widely used, imperfect step toward growing our fuel rather than pumping it from the ground.

Estimating Ethanol Use

To adjust fuel economy for ethanol blends, use the Ethanol Fuel Consumption Calculator. Compare cost per mile with the Fuel Cost Per Mile Calculator, and other alternative fuels via the Hydrogen Fuel Consumption Calculator.