The Caterpillar C13 is an inline-6 diesel internal combustion engine made by Caterpillar. The engine is 12.5 liters in displacement (763 cubic inches). The cylinder size is 5.12 × 6.18 bore/stroke.Engine ratings were available from 380–525 horsepower at 2100 RPM. The peak torque occurs at an engine speed of 1200 RPM.