Power
Many forklifts are made to run on propane gas. Propane-powered forklifts are very simple to refill. The gas is stored inside a pressurized tank on the rear of the truck. The propane is pushed into the engine, where it is converted into vapor and the vapor mixes with air. The throttle of the forklift is used to be able to control the flow of vapor. A spark plug ignites the air and vapor mixture producing pressure which makes the pistons move. The pistons turn the wheels and power the hydraulic pump.
Forklifts that use propane are suggested for use within warehouses and other buildings because they are clean burning with low emissions.
Hydraulics
What allows a forklift to raise and transport heavy objects from one location to another is the hydraulic system. Tubes, cylinders and a pump make up the hydraulic system. The pump forces dense fluid through the tubing and into the cylinders. The pressure build up pushes a piston, that raises the forks. When the forks are lowered by the operator, the hydraulic fluid flows out of the cylinders and back into the pump.
Steering
Propane forklifts work well where maneuverability is needed. Not like a car, a forklift makes use of its rear wheels to turn, that enables the forklift to pivot quickly on a tight radius.