Tanker trucks are used to haul fuel for local delivery as well as longer range transportation for fuels that are not locally available. Table 4-7 shows the emissions from heavy-duty trucks. ARB's EMFAC model estimates truck emissions for the average truckload and weight. These estimates are based on engine dynamometer results in g/bhp-hr which are converted to g/mi. The conversion factor implicitly takes into account driving patterns and vehicle loads that probably do not reflect those of tanker trucks. The Los Angeles County Metropolitan Transportation Authority has tested numerous heavy-duty vehicles on a chassis dynamometer. A series of tests were run on a truck whose emissions were tested at gross vehicle weights (GVW) ranging from 25,000 to 55,000 lb (Wool). Tank truck emissions are based on these chassis dynamometer tests. More stringent emission controls should results in lower NOx emissions for heavy-duty trucks. The 1990 NOx estimate corresponds to an engine that emits 5 g/bhp-hr. A 2 g/bhp-hr (or lower) NOx standard will apply to heavy-duty vehicles by 2010. Therefore, year 2010 NOx for all trucks in the United States are projected to be 40 percent of current levels.
Table 4-7: Heavy-Duty Truck Emissions
Fuel economy (mi/gal)
Source: LACMTA data, adjusted for load (Wool).
Table 4-8 shows the load carrying capacity of tanker trucks. The gallon carrying capacity depends on the liquid fuel density since the truck must meet axle weight requirements. The values shown in the table are typical for current fuel deliveries. For reformulated diesel, it is unlikely that the load will be varied to take into account small differences in fuel density.
Table 4-9 shows the distances for hauling fuels by tanker truck with the assumption of a central Los Angeles fueling location. The distances are based on a typical round trip to the appropriate fuel storage site. Petroleum fuels are stored in proximity to oil refineries in the SoCAB with many storage terminals along the coast (Wilmington, El Segundo, etc.). Methanol is currently stored at a chemical terminal in San Pedro. Some finished fuels are trucked further distances. Future biomass derived fuels may also be trucked into Los Angeles from outside the area.