Now that the summer driving season has come to an end, we have an estimate on how much U.S. motorists saved by running on the higher ethanol blend.

An analysis by the Renewable Fuels Association (RFA) calculates that an additional 194 million gallons of E15 were sold from June 1 to Sept. 15 due to a waiver that allowed the fuel to remain on the market nationwide during the summer.

With E15 priced at an average discount of 30 cents per gallon to E10, the study estimates that American drivers saved $57 million, even after figuring in a marginal drop in fuel economy of around 1.3% from using E15 compared to E10. Using E15 in place of E10 also reduces greenhouse gas emissions by about 3% and reduces emissions of the pollutants that lead to ground-level ozone and smog, the RFA noted.  

A separate study released by Growth Energy found that a nationwide transition to E15 could save drivers $20.6 billion in annual fuel costs.

The difference in price is easy to see every time you pull into a gas station that offers E15, which is approved for cars 2001 and newer, accounting for 96% of the vehicles on the road today. The fuel is currently sold at more than 2,700 stations across 31 states. One reason it isn’t more widely available is a regulatory technicality in the Clean Air Act that requires the summertime waiver.

If fuel retailers could rely on being able to sell E15 all year long, more of them would upgrade their infrastructure.

Let’s hope the technicality will be cleared up by next summer and we can all enjoy more savings at the gas pump.