Ideal Idle Idea

Kristen Simpson

With fuel prices spiraling upward faster than you can say “OPEC,” every refuse hauler is scouting for ways to achieve better fuel efficiency. Abilene, Texas, a city of 116,000 located about three hours west of Dallas, has found a way to do just that.

The city's Solid Waste Services Division has reduced fuel consumption among its refuse collection vehicle fleet by using trucks equipped with operate-in-gear-at-idle systems. The systems allow an engine to run at much lower revolutions per minute (RPM) and thus conserve diesel when compared with collection vehicles that do not have the technology.

“I've used it for several years, and I'm very pleased,” says Mike Wegner, Abilene's solid waste manager. “You're saving wear and tear, and you're saving fuel.”

The city's solid waste fleet has 16 Heil collection vehicles — 13 automated side loaders and three front loaders — that are equipped with an operate-in-gear-at-idle system and 12 other trucks that are not. Individually, the vehicles with the technology consume 15 to 20 percent less fuel than their counterparts, Wegner says.

Furthermore, the vehicles without the operate-in-gear-at-idle systems average 1.9 miles per gallon (mpg) of diesel. By contrast, the collection trucks with the technology have a fuel economy of 2.4 mpg, according to Wegner. Given the skyrocketing price of fuel, that's a meaningful difference. Wegner's division has been paying nearly $2.50 a gallon for diesel in 2006, up 15 percent from last year.

Operate-in-gear-at-idle systems save fuel by using a larger hydraulic pump that produces the extra flow of fluid needed for a refuse collection vehicle to load and compact garbage at standard speeds while the engine remains at idle. Without the systems, truck operators must shift the transmission and throttle the engine to power the hydraulic system every time they make a route stop or want to pack the load.

All of that shifting and revving burns precious fuel. It's noisy, too, a problem in residential neighborhoods. What's more, it tires the operator and accelerates wear on a vehicle's engine, chassis and transmission.

Time also is wasted when a truck doesn't have an operate-in-gear-at-idle system, Wegner explains. On each stop, a driver must shift the truck into neutral, rev the engine to load or compact, let the engine idle down, then finally shift back into gear and head to the next stop. The process piles seconds onto each pickup, wasted time that adds up over the course of a route. Wegner estimates that each of his vehicles fitted with the technology shaves an hour off the route.

“It's so much more efficient,” Wegner says. “You eliminate a thousand transmission shifts per day, per truck.”

With 28 routes covering nearly 35,000 homes and businesses in Abilene, the time savings add up, giving operators more opportunity to maintain their vehicles. The technology also helps cap fleet size, since fewer trucks can handle more routes. Fleet managers wanting to conserve fuel, save time and extend equipment life would be wise to consider the system, Wegner says.
— Kristen Simpson
President, Simpson Communications