New emission standards for county fleets will fuel budget increases

By Bob Stanton
Polk County, Fla.

Is your county prepared for the next generation of emission standards? Is it prepared to transition to a new diesel fuel? Is it prepared to incorporate new diesel engine technology into an already mixed fleet of diesel engines?

Ready or not, all three are inevitable and interrelated aspects of major emissions and environmental changes that will affect county vehicles and equipment within a short few months. Here are the facts:

• 2007 federal emission standards for on-highway diesel engines require significant reductions in nitrous oxide (NOx) and particulate matter (PM). To enable the new engine technology, fleets will be required to transition to Ultra Low Sulfur Diesel Fuel (ULSD). The fuel will available nationwide by September 2006.
• Federal emission standards for on-highway diesel engines tighten further in 2010 requiring further changes in vehicle engineering and engine technology.

In short, government fleets should prepare to transition to ULSD early and should budget for additional technical training, higher vehicle and fuel prices and specify their vehicles wisely to assure their preparations adequately address these issues.

Some particulars

Fleets intending to purchase on-highway diesel powered vehicles in 2007 and beyond must transition to ULSD. Failure to make the transition to ULSD will destroy the emissions devices being engineered for the 2007 engines causing major and costly damage to the engines themselves.

The transition to ULSD could be lengthy because several cycles of fuel deliveries will be required to purge residual sulfur remaining in both vehicle and bulk storage systems. Fleets may wish to engage in sulfur testing as their transition progresses to assure the sulfur content is being reduced effectively.

Fortunately, ULSD will be "backwards compatible" in that it can be used in pre-2007 engines with little or no change in performance. Although backwards compatible, fleets wishing to continue using current low sulfur diesel must segregate their fuel stocks and take steps to prevent the entry of #2 LSD into vehicles equipped with post-2006 engines. By Dec. 10, 2010, #2 LSD will no longer be permitted for use in the United States making the transition inevitable by then.

As fleets engage in this transition, they should be prepared for higher fuel prices, a reduction in miles per gallon due to ULSD’s lower BTU, possible lubricity issues in older engines, and fleets in northern climates may need to address a lower tolerance to cold temperatures attendant with ULSD.

ULSD is specifically formulated to enable diesel engine technology designed to meet the tighter 2007 federal emission standards. The new technology is largely built on the cooled exhaust gas emission designs recently incorporated in 2002 diesel engines. In addition to cooled EGR’s, engine manufacturers will add particulate matter filters, larger cooling systems, oxidation catalysts and some will add variable geometry turbochargers and redesigned fuel injection technology.

The particulate matter filters will be a standard component on post-2006 diesel equipped vehicles. In addition to their filtration requirement, many of these filters will engage in automatic active regeneration where a small quantity of fuel is injected into the filter to facilitate burning of the particulate matter contained therein. This fuel injection process will heat the filter to 900 degrees. In government applications such as fire apparatus and other vocational uses, the placement of this filter will be a critical consideration in vehicle specifications to assure the proper placement of other frame mounted equipment as well as assuring the protection of the surfaces underneath the vehicle when parked at idle on a job or fire site.

These devices will require diagnostic monitoring and periodic servicing all of which will require higher levels of technical training. A new diagnostic system (EMD) is being developed for this purpose and will apply to diesel powered vehicles rated above 14,000 lbs GVW and produced after January 2007. Servicing the particulate matter filters may require hazardous materials protection in addition to their servicing requirements.

Because engine temperatures and air management are critical to the effectiveness of this technology, a new motor oil (API CG Ð 4) is being formulated for these engines. It’s unknown if the new oil will itself be backwards compatible and allowed for use in older engines. If not, fleets will be forced to inventory the new motor oil for use in the new engines. It’s also possible that oil change intervals may be reduced. In addition to the new oil formulation, a new antifreeze formulation may be required for the same reasons.

In 2010, emission standards tighten further and current technology options are limited to selective catalytic recovery involving the injection of a urea compound into the exhaust stream. This method, currently being used in Europe, has particular difficulties in the United States, and it’s hoped that engine technology will develop beyond SCR in time to meet the new standards.

(Bob Stanton is the director of fleet management, Polk County, Fla. He can be reached at BobStanton@polk-county.net or 863/534-5660.)