Dual Fuel Engine
DF or Duel Fuel Engines are the type of engines that could operate on a mixture of gas fuel or diesel fuel or it could run on diesel fuel alone. Duel Fuel engines can not operate on gas alone since they do not posses an ignition system, nor do they possess any spark plugs.

Because diesel is not a pure gas, and it is not a pure diesel designed engine, it has some disadvantages in the department of fuel efficiency, as well as Methane slippage.. Like for example, the fuel efficiency may be 5% to 8% less than in a comparable lean-burn, spark-ignited engine at 100% load. It can even be greater on lower loads.

Lift Truck Classification and Fuel Sources
There are some applications which have proved difficult for the forklift. For example, scrap metal is among these issues. In order to successfully handle items like this requires utilizing the correct kind of machine for the task.

There are 7 major lift truck classes, including power sources such as liquid propane gas, hydrogen fuel cell, diesel, electric and gasoline. The power source is linked to some of these specific classes. The main power sources for forklifts include Battery, Diesel, Gasoline, Propane and Fuel Cell.

Electric powered trucks are the most popular, mainly Class I, II and class III forklifts. Internal combustion engines are more common in Classes V and IV. The most common electric power source is the lead-acid battery. Among internal combustion trucks, approximately over 90% are fueled by propane.

The most popular power source for lift trucks is battery. Battery fueled models make up about 60% of the new forklifts sold within the USA. Their benefits consist of: less maintenance requirements, quiet operation, the ability to be utilized indoors and outside with no harmful emissions.