Dual Fuel Engine
DF or Duel Fuel Engines are the type of engines which could work on a mixture of gas fuel or diesel fuel or it can operate on diesel fuel alone. Duel Fuel engines could not run on gas alone as 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.. For instance, the fuel efficiency can be 5% to 8% less than in a comparable lean-burn, spark-ignited engine at 100 percent load. It could even be greater on lower loads.

Lift Truck Fuel Sources and Classifications
There are some recycling materials handling applications that can prove very difficult for lift trucks. Like for example, scrap metal is one of these problems. To be able to successfully handle items like this needs utilizing the right type of machinery for the task.

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

The most common overall are electric powered trucks, mostly in Class III, II and class I forklifts. In Classes V and IV, internal combustion trucks are more popular. The most common electric power source is the lead-acid battery. Among internal combustion trucks, roughly more than 90% are fueled by propane.

The battery is the forklifts most common power source. Battery fueled models make up around 60 percent of the new forklifts sold in the United States. Their benefits include: less maintenance requirements, quiet operation, the ability to be used indoors and outside with no harmful emissions.