Fuel for Thought

By Fern Abrams, American Trucking Associations

Issue: Cutting fuel consumption can help your bottom line and the environment . With the price of diesel fuel up more than 50% over last year, fleets are looking for innovative ways to lower their fuel consumption.

One of the most obvious is to limit idling time. This is not only a good environmental policy, but a good business policy as well when you consider that trucks consume about eight-tenths of a gallon of fuel per hour when they're idling. Although an idling truck emits only a fraction (8%-15%) of the pollution it emits while operating on the road, that's still quite a bit when you consider that the fuel isn't getting your freight any closer to its destination. In fact, it's been estimated that over the course of a year truck idling adds approximately 59,000 tons of smog-forming nitrogen oxides (NOx) and 97,000 tons of carbon monoxide to the air.

The Maintenance Council (TMC) of the American Trucking Assns. estimates that idling for only one hour per day for a year results in the equivalent of 64,000 miles of engine wear and wastes over 500 gallons of fuel. The Dept. of Energy estimates that, as an industry, trucking wastes 900-million gallons of diesel fuel each year - to go nowhere. From either an environmental or an economic standpoint, excessive idling makes no sense.

Although many cities and towns have idling ordinances, the federal government currently has no policy limiting vehicle idling and a little more than a dozen states have explicit laws against excessive idling. However, in most states, trucks and buses that are idling can be ticketed under state nuisance laws. Many fleets already have rules in place to limit driver idling time. Leading the movement is United Parcel Service, which has placed an outright ban on idling, no matter how briefly a vehicle is stopped.

Other fleets have installed equipment that automatically turns off the engine when a vehicle has been idling for a time. However, this equipment can be set so that it doesn't shut off the engine when the outside temperature is low enough to affect driver comfort. Keeping drivers warm while they sleep can present a problem. If a driver has to run the engine to keep warm, then vehicle idling and wasted fuel will both increase. But there are other options. Small, diesel-fired auxiliary heaters are used to provide fast, direct heat to drivers.

A study done by Argonne National Laboratories last year estimates that auxiliary heaters, which use only one-tenth as much fuel as an idling engine, can save over 1,230 gallons of fuel per truck in one year. With basic models priced at about $1,000, auxiliary heaters make economic sense for fleets facing steep fuel costs. Premium models that provide cooling are also available. Auxiliary heaters have been popular for years in Europe, where diesel costs more than $4/gal. Until fairly recently, however, they have had little penetration in the U.S. market. But with escalating fuel prices, this, too, may change.

Another way to limit fuel consumption is to control the speed of your vehicles. Trucks burn an additional one-tenth of a gallon of fuel for each mile-an-hour increase in speed. Some fleets have instituted bonuses for drivers based on lower rates of fuel consumption. And finally, we can't forget the importance of proper vehicle maintenance in improving fuel economy. One symptom of a possible maintenance problem is truck smoke. Since most smoke is really unburned fuel, reducing smoke is a good way to reduce fuel consumption. If your vehicles are spewing dark black smoke, it usually means incomplete combustion. White smoke, on the other hand, probably indicates that droplets of unburned liquid fuel and water vapor have formed, most likely at startup or idle.

For more information on how to improve fuel economy, ask TMC for a copy of The Fleet Manager's Guide to Fuel Economy. It offers dozens of tips, ranging from proper tire inflation to driver training. Remember, saving fuel is twice blessed: It improves your bottom line, as well as the air we breathe.

Fern Abrams is the manager of environmental affairs at the American Trucking Association.