Power
Numerous forklifts are made to operate on propane gas. Forklifts which use propane 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 throttle of the forklift is used to control the vapor flow. A spark plug ignites the vapor and air mixture creating pressure which makes the pistons move. The pistons turn the wheels and run the hydraulic pump.

Forklifts that use propane are recommended for use inside warehouses and other buildings because they are clean burning with low emissions.

Hydraulics
What enables a forklift to raise and move heavy objects from one place to another is the hydraulic system. Tubes, cylinders and a pump make up the hydraulic system. The pump forces dense fluid in 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 necessary. Not like a car, a forklift makes use of its rear wheels to pivot, which allows the forklift to turn quickly on a tight radius.