Dual Fuel Engine
DF or Duel Fuel Engines are the kind of engines which could work on a mixture of gas fuel or diesel fuel or it could work on diesel fuel alone. Duel Fuel engines could not run on gas alone as they do not have an ignition system, nor do they have any spark plugs.

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

Lift Truck Classification and Fuel Sources
There are certain recycling materials handling applications that can prove very difficult for lift trucks. Like for example, scrap metal is among these problems. To be able to successfully handle items like this requires using the correct type of machinery for the job.

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 Battery, Diesel, Gasoline, Propane and Fuel Cell.

The most popular overall are electric powered trucks, mostly in Class I, II and class III 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, about over 90% are propane powered.

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