Power
Numerous forklifts are made to run on propane gas. Propane-powered forklifts are really simple to refill. The gas is stored in a pressurized tank on the truck's back. The propane is pushed into the engine, where it is converted into vapor and then the vapor mixes with air. The throttle of the forklift is used to control the vapor flow. A spark plug fires up the vapor and air mixture producing pressure that makes the pistons move. The pistons turn the wheels and power the hydraulic pump.

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

Hydraulics
What allows a forklift to raise and move heavy things from one place to another is the hydraulic system. 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 operator lowers the forks, the hydraulic fluid flows out of the cylinders and back in the pump.

Steering
Propane forklifts work well where maneuverability is necessary. Not like an automobile, a forklift makes use of its back wheels to pivot, which allows the forklift to pivot quickly on a tight radius.