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

As the engine is not a pure diesel engine and diesel is not a pure gas, this machine does suffer from Methane slippage and fuel efficiency. Like for instance, the fuel efficiency can be 5% to 8% less than in a comparable spark-ignited, lean burn engine at 100 percent load. It could even be lower or higher loads.

Lift Truck Classification and Fuel Sources
There are some applications that have proved difficult for the forklift. Like for example, scrap metal is one of these problems. In order to successfully handle items like this needs using the right kind of machinery for the task.

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

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

The battery is the forklifts most popular power source. Battery fueled units make up approximately 60 percent of the new forklifts sold within the USA. Their benefits consist of: less maintenance requirements, quiet operation, the ability to be used outdoors and inside with no harmful emissions.