It’s okay
to go low.

Unleaded 88 and Unleaded 87 are commonly the lowest prices at South Dakota gas stations. The only difference between the two is the exact amount of ethanol in the blend. Unleaded 88 is made with up to 15% ethanol (E15), while Unleaded 87 is made with 10% ethanol (E10). The more ethanol in the fuel, the higher octane it has, so that’s why Unleaded 88 gets the bigger number at the pump.

Source: Alternative Fuels Data Center

When it comes to mileage, there’s basically no difference between gasoline with an ethanol blend and regular gasoline. But when you consider the price, you will go farther per dollar with blended fuel.

Source: FuelEconomy.gov

Nearly all cars, trucks and SUVs on the road today can run on Unleaded 88 (E15) and Unleaded 87 (E10) — so yeah, chances are yours can too! In fact, most of the gasoline sold in the U.S. contains some amount of ethanol.

Source: FuelEconomy.gov

Fermentation is the most common method for converting plant starches and sugars into ethanol. During fermentation, microorganisms metabolize the plant matter, and as a result, produce ethanol. That ethanol is then blended with gasoline.

And guess what? One of the most abundant sources of plant matter used in this process is found right here in South Dakota: Corn.

Source: Department of Energy

Ethanol fuels, like Unleaded 88 (E15) and Unleaded 87 (E10), have a proven track record of cutting greenhouse gas emissions from transportation. According to the Department of Energy’s Argonne National Laboratory, they decrease emissions by 44 to 52% compared to regular gasoline. 

Researchers from Harvard, MIT and Tufts concluded pretty much the same thing with an average reduction of 46% compared to gasoline.

Source: Renewable Fuels Association

No. Using corn for ethanol does not have a significant impact on food prices. Critics of biofuels promote a theory that ethanol “eats up” food supplies, but the truth is that the increasing demand for biofuels helps farmers to invest in efficiencies to better utilize existing cropland, allowing them to supply more food and energy. Ethanol production only utilizes the starch in each kernel, while the rest of the fat, fiber and protein goes into animal feed in the form of distillers grains. This by-product creates one of America’s largest sources of animal feed which in turn shows up in the grocery store in the form of meat products such as hamburger, steak and bacon.

Source: Growth Energy

All ethanol fuels are biofuels, but not all biofuels are ethanol fuels. Ethanol is a type of alcohol that can be blended with gasoline and burned in modern engines. While ethanol is typically made from plant matter, biodiesel, another type of biofuel, can be made from vegetable oil, animal fat, and even used restaurant grease. It is not blended with gasoline.

Source: Energy.gov

At a few gas stations in South Dakota, you might see two buttons labeled “87” at the pump. Even though they have the same number on the button, only one of them has ethanol (E10), and the other is regular gasoline with the same octane rating. Which is which? The one with ethanol (E10) is also the one with the lowest price.