The Gray Tractor 18-36 is a standard-tread tractor built by Gray Tractor in Minneapolis, Minnesota, USA from 1918 to 1921. It features a Waukesha 7.8L 4-cylinder liquid-cooled gasoline engine with a 2-speed gear transmission. The tractor delivers a claimed drawbar power of 18 hp and belt power of 36 hp, with tested drawbar and belt powers slightly higher and lower respectively. It has a 3x1 drum drive with manual steering and an open operator station. Dimensions include a 104.5 inch wheelbase, 174 inch length, 72.25 inch width, and 72 inch height, weighing 6200 lbs. Tires are 40x8 steel front and 54x54 steel rear. The serial number plate is located on the left side of the tractor on top of the transmission case.