Power
Many forklifts are made to operate on propane gas. Propane-powered forklifts are easy 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 forklift throttle is used to be able to control the flow of vapor. A spark plug ignites the mix of air and vapor producing pressure which makes the pistons move. The pistons run the hydraulic pump and turn the wheels.
Since the types of forklifts that are operated by propane are clean burning and have low emissions, they are suitable to be utilized within warehouses and other buildings.
Hydraulics
The forklift's hydraulic system is what allows it to lift and transport really heavy stuff from location to location. A pump, tubes and cylinders 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 lifts 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 required. Not like a car, a forklift makes use of its rear wheels to turn, that allows the forklift to pivot fast on a tight radius.