By Mike Antich
There’s a direct correlation between vehicle weight, fuel economy, and greenhouse gas (GHG) emissions. To find the right equilibrium, you need to right-size the vehicles in your fleet. One form of right-sizing is transitioning to smaller-displacement engines. The cyclical volatility of gasoline prices during the past decade has been the catalyst for many companies to switch to four-cylinder engines. Another reason to downsize engines has been to achieve goals established in corporate-wide sustainability programs requiring GHG emissions reductions. One example is Merck, which established a corporate-wide initiative to reduce GHG emissions of its global fleet by 12 percent in 2012 from base-year 2005. One prong of this multipronged strategy is to increase the number of four-cylinder models in the U.S. fleet.
Switching to four-cylinder engines allows fleets (that are primarily automobiles) to maintain the same-size vehicles necessary to meet fleet applications without downsizing to smaller classes of vehicles. Helping to facilitate the migration to smaller engines has been the incremental horsepower improvements in smaller displacement, fuel-efficient engines. Nowadays, some high-volume fleet models are only equipped with four-cylinder engines, without a V-6 option.
Growing Number of Fleets Right-Sizing
In addition to ballooning fuel budgets and meeting sustainability objectives, another reason for right-sizing is changing business practices. “Our business practices have evolved over the years to the point where we can use smaller and lighter vehicles for our field service technicians,” said Frank Felicetta, director − fleet operations for Cablevision, headquartered in Bethpage, N.Y.
Another fleet in the midst of a multiyear right-sizing initiative is OTIS. “We started the vehicle downsizing process two years ago. This process will continue and no opportunity will be ignored to downsize vehicles,” said Phil Schreiber, fleet manager, North America for OTIS Service Center in Bloomfield, Conn.
Similarly, Brown-Forman is implementing an initiative to downsize its fleet vehicles. “Two years ago, the SUV was the major vehicle in our fleet. Last year, we started to downsize to the crossover — large, mid, and small size,” said Mary Pat Crabtree, fleet & relocation manager for Brown-Forman in Louisville, Ky. “After months of discussion with management, it was concluded a mid-size sedan is the most appropriate vehicle.”
Likewise, Carrier Corp. is reducing fuel and global GHG emissions through alterations and upgrades to its 3,000-vehicle fleet. Since 2006, Carrier reduced emissions by more than 30 percent through a variety of techniques, such as right-sizing and eliminating unnecessary weight during transport.
Other fleets have adopted a minimum fuel economy target for new models entering their fleets, such as Red Bull North America, Inc. “We have downsized our vehicles and put a minimum 23 mpg combined restriction,” said David McCauley, fleet manager for Red Bull North America.
Spec’ing Lighter Weight Vehicles
Ultimately, fleet application dictates vehicle size. However, it is possible to spec a lighter vehicle without going down a class. When spec’ing vehicles, compare the weight of major components. For example, some engines weigh several hundred pounds less than others with the same horsepower and torque. Some pumps are much lighter than others for similar flow and pressure ratings. Aluminum wheels can save hundreds of pounds over steel wheels, especially for trucks, depending on the number of axles.
Individual weight savings start adding up, and proper specifications can eliminate a lot of weight before a vehicle goes into service. For instance, an oversized fuel tank adds unnecessary weight. Unless the vehicle will be used in an area where fuel isn’t easily accessible, why carry around three or four days’ worth of fuel? A gallon of gasoline weighs 6 lbs. and a gallon of diesel fuel weighs 7 lbs. Factor in the weight of the fuel tank, and carrying 50 extra gallons of fuel could mean needlessly hauling up to 400 lbs. Similarly, look closely at upfit equipment and consider alternative, lighter versions to get the job done, such as lighter weight bodies using high-tensile steel or composites.
Every pound of extra weight requires an engine to work harder, decreasing fuel economy. Similarly, every pound deleted from curb weight not only reduces emissions, but can be directly converted into revenue-generating payload. Vehicles get better fuel mileage when not loaded with unnecessary weight. An extra 100 lbs. in a vehicle could reduce mpg up to 2 percent. The reduction is based on the percentage of extra weight relative to a vehicle’s weight and affects smaller vehicles more than larger ones. However, right-sizing a payload-carrying truck to improve fuel economy requires caution. Some fleets, for example, have sought better fuel economy (and lower acquisition cost) by replacing larger trucks with lower GVW trucks. However, this increases the risk of overloading, which will create an unsafe vehicle and result in needless liability exposure in the event of an accident. This risk can be easily avoided by simply following OEM specifications.
In the final analysis, right-sizing the vehicles in your fleet, reduces fuel consumption, which will reduce GHG emissions. When it comes to greening your fleet, right-sizing is the right thing to do.
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