The Caterpillar Diesel Sixty-Five is an agricultural crawler tractor produced from 1931 to 1932 by Caterpillar in Peoria, Illinois, USA. It features a Caterpillar D9900 4-cylinder liquid-cooled diesel engine with a displacement of 17.9 liters, rated at 700 RPM. The tractor has a 3-speed gear transmission with 3 forward and 1 reverse gears, and a crawler drive. It has an open operator station and weighs 24,400 lbs (11,067 kg). The Diesel Sixty-Five delivers tested drawbar power of 65.11 hp and belt power of 77.08 hp. A total of 157 units were built.