The objectives of this work were to document the benefits of the use of natural gas as a vehicle fuel in three classes of vehicles. The vehicles classes that were of interest were:

  1. Light duty vehicles using compressed natural gas, with a focus on full size passenger cars and vans.
  2. Medium duty vehicles that could be fuelled with either compressed or liquefied natural gas. These might be refuse haulers or urban buses.
  3. Heavy-duty trucks that use liquefied natural gas and the Westport Cycle engines.

For each of these classes of vehicles the impact that the fuel and engine has on greenhouse gas emissions, on the cost effectiveness of the greenhouse gas emission reduction and on criteria air contaminants were calculated and reported.