Class 5 Internal Combustion Engine Trucks (pneumatic tires)
Class 5 trucks are similar to Class 4 trucks, but have pneumatic tires, making them desirable for indoor or outdoor applications. They are powered by LP gas, gasoline, diesel or compressed natural gas. They are usually counterbalanced. These sit down riders are the most common type found in warehouse use.
Class 6 Electric and Internal Combustion Engine Tractors (solid and pneumatic tires)
These vehicles are not, in fact, forklifts at all. They are tractors. They may be powered by electric or any type of gas.