The Satoh ST-3840 is a utility tractor produced from 1980 to 1982. It features a Mitsubishi 1.5L 4-cylinder liquid-cooled diesel engine producing 38 hp (28.3 kW) at 2700 RPM. The tractor has a 15-speed transmission with 15 forward and 3 reverse gears, four-wheel drive, and an open operator station. It weighs 3064 lbs (1389 kg). Variants include the ST-3820 2WD, ST-3840 4WD, and Mitsubishi-powered D3850 and D3850FD models.