February 2010, Automotive Fleet - Feature
Staples Fleet Tests Diesel-Electric Viability
In greening its fleet, Staples goes to great lengths to pair an electric propulsion system with a diesel engine and urges other fleets to demand more from OEMs to more closely meet their needs.
By Chad Simon
Framingham, Mass.-based Staples recently concluded a fleet-wide hybrid-diesel pilot program in Los Angeles designed to test the electric launch capability of a torque-assistance (bolt-on) hybrid technology, identify its viability, and determine whether it could work with the fleet's current Isuzu diesel powertrains, according to Mike Payette, fleet equipment manager for Staples.
Payette oversees a fleet of 2,200 vehicles comprising Isuzu N-Series and FTR; International MaxxForce 255 4300; and Freightliner M2 Class 5, 6, and 7 medium-duty trucks. The fleet is wrapping up another hybrid pilot program in Boston.
Turning to Isuzu
When deciding which selector to use, Payette turned to Isuzu, telling company officials he wanted to reduce his $40,000-$50,000 daily fuel spend.
"Anything I can do to save a nickel per truck per day comes out to a lot of money at the end of the year," Payette said. "From our drivers' standpoint, Isuzu has made very few changes in its cab design over the years, so whether we operate a 1994, 1998, or 2004 model, the cabs are essentially the same, the trucks operate in the same way, and all the buttons are in the same place. It's easy from a fleet standpoint to move the vehicle around from driver to driver."
According to Payette, Isuzu customers in the U.S. who want a hybrid application must install an aftermarket bolt-on hybrid drive system. However, this also allows fleet customers to spec how many trucks to hybridize or remain conventional diesel, depending on driver route structures.
Searching for an Answer
Staples' fleet completes 48-52 stop-and-go deliveries per truck per day, an operation well suited to electric- or hybrid-drive technology. However, following the Los Angeles pilot program, Payette and his team concluded the simple bolt-on aftermarket hybrid system used in the test wasn't the way to go.
Instead, Payette believes the system must be offered by OEMs as part of an entire powertrain package. A true electric-launch system that can handle the peak horsepower and torque needs of the launch should be paired to a much smaller internal combustion engine that gets more than 25-30 mpg just to maintain the vehicle's speed.
"For instance, if an Isuzu truck runs a 5.4L four-cylinder diesel with a bolt-on hybrid system used to electrically launch the vehicle, once that vehicle gets up to speed, it still has a 210-hp, 5.4L diesel when all that is needed is about 130 horses to maintain the truck's speed," Payette said.
According to Payette, Isuzu acknowledges a 210-hp engine is not needed with the proper hybrid system bolted between the engine and transmission. However, the manufacturer currently does not offer a smaller diesel engine certified to meet U.S. emissions standards.
The Staples 2,200-unit fleet includes Isuzu N-Series and FTR; International MaxxForce 255 4300; and Freightliner M2 Class 5, 6, and 7 medium-duty trucks.