The Fleet Engineers AeroFlap, No. AF-19, is a 19" wide mud flap that accommodates wide-base tires. The mud flap, available in various lengths and in black or white with straight or angled top edges, has a diamond-patterned design that allows air and water to flow through the flap, reducing vehicle drag and increasing fuel mileage. According to the company, on-highway studies indicate that the AeroFlap increases fuel efficiency from 0.5 to 1 percent. Because air and water flow through, the vacuum that trails traditional mud flaps is broken up, thus reducing rain spray. The increased airflow also serves to vent heat away from tires and brakes.