By Mike Antich

There's a direct correlation between vehicle weight and fuel economy. 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. Typically, the chief culprit responsible for accumulating unnecessary weight is drivers.

Over the course of a vehicle assignment, drivers accumulate a "cargo" of dated sales materials, point of sale demos, and seldom-used tools carried in trunks, storage bins, and back seats. You'd be surprised how quickly lbs. add up, especially when heavy tools and materials are carried. Not only are trunks filled with work-related materials, but they are also used for personal storage.

I was told of one rep who would buy in bulk several boxes of one-gallon bottled water (a cumulative 16 gallons per box) and leave the boxes in the trunk because they were too heavy to carry into her home. She would remove from the trunk a gallon or two at a time, whenever water was needed. In the meantime, she hauled this unnecessary weight while conducting company business.

Every additional pound of extra weight in a vehicle requires an engine to work harder, decreasing fuel economy. If drivers emptied their vehicle of unnecessary items, there would be less demand on the engine, increasing fuel economy.

Fleet managers should institute a program to instruct drivers on a quarterly basis to remove all unnecessary items from their vehicles. This constant re-communication is critical because it is amazing how quickly drivers revert to old habits. It is important to make drivers energy conscious. Similar to the habit of turning lights off in unoccupied rooms at home, drivers should practice comparable energy conservation habits with their vehicles. Ask field managers to enforce these fuel saving tips and discourage drivers from using their vehicles as "rolling warehouses" to carry everything they may possibly need - just in case.

In terms of trucks, ask drivers to eliminate all unnecessary equipment and shelving, and carry only needed items. If given leeway, drivers will carry everything they can conceivably fit in a vehicle. It is important to develop guidelines as to what can be carried in vehicles relative to tools, passengers, and payload. Not only does overloading consume additional fuel, it poses a safety risk and causes unnecessary vehicle wear and tear.

In Snow Belt regions, during winter months, ask drivers to remove snow and ice left on the vehicle, which decreases gas mileage by disrupting air flow and increasing vehicle weight. Flying snow and ice are also dangerous for those driving behind. Similarly, roof top racks and carriers disrupt air flow and decrease fuel efficiency. Take these items off when not in use, and whenever possible, carry necessary items to the job, inside the vehicle.

Spec'ing Lighter Weight Vehicles

Fleet application dictates vehicle size. 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 hundred 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 available lighter versions that can get the job done. Examine if lighter weight bodies using high-tensile steel or composites would be appropriate for the fleet application. Every pound deleted from curb weight can be directly converted into revenue-generating payload.

Fatter Drivers Consume More Fuel

Although there is little fleet managers can do about this, it is interesting to note that fuel consumption has increased as U.S. workers have become heavier, according to studies by the University of Illinois at Urbana-Champaign and Virginia Commonwealth University. Americans are using 938 million more gallons of fuel annually than they were in 1960 as a result of extra body weight. Increased body weight is directly linked to decreased fuel economy. At $2 a gallon, the cost for overweight people driving vehicles amounts to $1.8 billion a year. Cumulatively, each extra lb. of body weight consumes more than 39 million gallons of extra gasoline each year.

The Best Time to Start is Now

There is a tendency to procrastinate before starting a diet. But dietitians will tell you the best time to start a diet is right now.

Isn't now the time for you to put your fleet on a diet?

Let me know what you think.

mike.antich@bobit.com