According to the Minnesota Department of Commerce, E15 sales in July was 220,571 gallons, bringing the total sold in the first seven months of the year to 2.99 million gallons. In 2015, a total of 3.09 million gallons of E15 was sold. 

Nonetheless, the volume of 220,571 gallons in July was the lowest volume recorded so far in 2016 as the EPA-imposed Reid Vapor Pressure (RVP) continued to have adverse effects on E15 sales.

The RVP bars the sale of E15 to non-flex fuel vehicles from June 1 to Sept 15. You can read more on the RVP ban on E15 here.

Prior to June, E15 sales in Minnesota this year averaged 500,000 gallons a month. In fact, in May, E15 sales were 530,766 gallons, the highest volume ever recorded in the state. But as RVP kicked in, sales fell by 57 percent to 224,860 gallons in June. In July, the volume slid further, albeit at a much smaller scale, to 220,571 gallons. 

The RVP doesn't apply to flex fuels. As such, retailers rebrand E15 as a flex-fuel during the RVP months.

Still, it doesn't seem likely that all the E15 consumed in both June and July were in flex fuels vehicles as there are other cheaper options like E30 and E85 for flex fuel vehicle owners. As such, it shows that despite the RVP ban, there is still strong demand for clean fuels like E15 in Minnesota.

Meanwhile, the Department of Commerce said in a report that E85 sales, based on data from the Minnesota Department of Revenue, was 1.09 million gallons in July, slightly lower than the 1.15 million gallons sold the month before. 

The price difference between regular unleaded and E85 in June was 47 cents per gallon on average. In July it dropped to 44 cents per gallon.