The Caterpillar C13 is an inline-6 diesel internal combustion engine made by Caterpillar. The engine is 12.5 litres in displacement (763 cubic inches). The cylinder size is 5.12 x 6.18 bore/stroke. The engine can produce 380-430 horsepower at 2100 RPMs. The peak torque RPM level is 1200 RPMs. The engine weighs over one ton at 2610 pounds. The Cat C13 is often used in Class 8 vehicles (tractor-trailers). The Gleaner A85 is a Gleaner combine harvester that uses the C13, and it is considered a class 8 vehicle. In the A85 as well as in fire trucks, it is rated at a higher horsepower.