Natural gas engines are even turning up in boats and trains, demonstrating the wide range of applications now available for this gaseous fuel. It is a clean burning fuel relative to either gasoline or diesel. Natural gas is among the safest fuels on the road today. While diesel is inherently safer than gasoline, natural gas is lighter than air and dissipates into the atmosphere if a leak occurs. Additionally, it is stored in above-ground tanks, eliminating problems associated with leaking underground storage tanks.
Natural gas is abundant and domestic.
Mack has experimental garbage trucks in Boston and New York City. These vehicles use engines redesigned to take advantage of natural gas's 130 octane rating. Because natural gas bums at about 1,200 degrees F and diesel ignites at about 650 degrees F, a spark-plug has to be added to the typical diesel engine block to enable the engine to use natural gas. This requirement effectively changes the engine from compression ignition to spark ignition. In this option, the compression feature of the diesel is retained.