The R-11 Refueler replaced the R-9 Refueler as the primary mobile refueling vehicle for The United States Air Force. There are currently three models of the R-11. The first generation was delivered in 1989 to the Air Force by the Oshkosh Truck Corporation and is commonly referred to as the Oshkosh R-11. The Air Force purchased 1,250 Oshkosh R-11s between 1987 and 1991. Deliveries of the 2nd generation R-11 began in 1994. The contract for the 2nd generation model was awarded to the Kovatch Corporation, and the pumping and dispensing systems are mounted on a Volvo chassis. These models are commonly referred to as the Volvo R-11. Deliveries of the 3rd generation R-11 began in 2004. The contract for this model was also awarded to the Kovatch Corporation, and the pumping and dispensing systems are mounted on an International chassis. This model is commonly referred to as the International R-11.
R-11 fuel tanks hold a maximum capacity of 6,000 US gallons (23,000Â L) and are able to issue fuel at a rate of 600 US gallons (2,300Â L) per minute.