Oil companies could be blending more ethanol with gasoline, but use deceptive practices to avoid doing so, according to Bob Dinneen, president of the Renewable Fuels Association. The issue centers around Renewable Identification Numbers (RINs), a type of credit refineries can use to comply with the Renewable Fuels Standard (RFS).

The RFS sets mandatory blend levels for renewable fuels, with the target increasing annually. The RFS for 2013 is 16.55 billion gallons. By 2022, the RFS grows to 36 billion gallons.

According to the Renewable Fuels Association, a RIN is produced when a gallon of renewable fuel is produced. Oil companies can then split the RIN from the gallon when they buy the gallon of renewable fuel and sell it on the open market. Oil companies can either buy a gallon of renewable fuel to comply with the RFS or buy a RIN credit on the open market.