The average U.S. pump price for diesel exhaust fluid (DEF) dropped sharply between June and July this year, falling by 28 cents, or 10%, to an average of $2.70 per gallon, according to data tracked by Integer Research.

The fall comes after four straight months of rising prices and this is the lowest average price recorded since the firm launched its DEF Tracker service in October 2011, notedChris Goodfellow, an emissions analyst with Integer.

“The decrease in price has been caused by the falling cost of urea – the raw material used in the production of DEF – and the level of competition between truck stops, with both Love’s and Pilot introducing a series of price reductions during July,” he explained to Fleet Owner. “These two truck stop operators account for 79% of the bulk DEF pump network.”

Goodfellow noted that Love's Travel Stops, which offers bulk DEF pumps at 150 of its locations, introduced a lower national pump price of $2.39 per gallon during July.

He added that the average price of bulk DEF delivered to fleets by tote or to permanent storage installations fell in each of the six U.S. cities monitored by the firm, with the exception of Tampa, FL, which recorded a one cent increase in its average tote price.