Medium and heavy duty trucks and buses typically use large amounts of fuel due to the combination of low fuel economy, heavy gross vehicle weight, and, in some cases, long distances traveled. The high fuel consumption of these vehicles is motivating fleet managers to find strategies to reduce both the fuel costs and the environmental impact of their fleets. Owing to substantial and rising supplies of low-cost natural gas (NG), and the substantially lower greenhouse gas (GHG) emissions of natural gas vehicles, natural gas has become an increasingly attractive choice for a transportation fuel.
