Fewer oil changes help city save money
Montebello, Calif., is saving thousands of dollars and helping the environment through use of a filter that recycles oil during vehicle operation. The city has extended oil change intervals and reduced the incidence of engine failure in its bus fleet, according to Vehicle Maintenance Manager Robert Cavazos. Compliance with federal Executive Order Nos. 12856 and 12873, which require government and military agencies to reduce their waste oil generation 50 percent by December 1999, is another anticipated benefit.
Montebello Bus Lines’ 54 buses each average 3,500 miles per month. As is typical with heavy duty diesel engines, the buses’ engines have both primary and secondary filtration systems intended to eliminate particulates and moisture from the oil.
The secondary oil filtration system previously used was difficult to maintain and did not work well, according to Cavazos. “We were losing engines left and right because of the bad filtration system,” he says. In fact, the city needed to have at least 10 bus engines rebuilt (at a cost of about $18,000 apiece), largely because dirty oil caused excessive wear on internal engine parts. Every 6,000 miles the secondary filter in each bus was replaced, and the oil (30 quarts) was changed.
About two years ago, Montebello switched to an onboard recycling system from OilGuard, Vista, Calif. Employing technology used in the medical field by kidney dialysis machines, the filter diverts a small stream (about 5 to 7 percent) of the engine oil through the core, then returns it to the main oil flow. It is capable of filtering out particles below 3 microns in size, as opposed to the 30- to 40-micron range for conventional factory filters.
Since converting to the system, Cavazos’s staff changes oil and filters every 12,000 miles, an interval he says is conservative and could be extended by another 6,000 miles with no adverse effects. Because of a dramatic reduction in engine failures and less money spent on oil and filters, “We’re probably saving thousands of dollars per year,” Cavazos says.
National Pollution Abatement Services, the environmental division of the filter manufacturer, recommends the following steps for extending oil change intervals: * Use high-grade lube oil; * Maintain a consistent, professionally administered oil analysis program; * Train service personnel in correct oil change procedures (up to 20 percent of oil contaminants are left in the engine when the oil change is done improperly); and * Customize the lube change schedule to fit a particular fleet’s needs. One size does not fit all.