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 %. The reduction is based on the percentage of extra weight relative to a vehicle’s weight and affects smaller vehicles more than larger ones. One of the chief culprits responsible for accumulating unnecessary weight onboard a vehicle 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 unnecessary pounds 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 pound of additional 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. In addition, a lighter weight improves acceleration and braking.

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 fact, in pre-pandemic days, one fleet manager (and avid bowler) admitted her own guilt in keeping her personal set of bowling balls in the trunk of her company vehicle.

In terms of vocational 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, but it also 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. 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 a remote  area where fuel isn’t easily accessible, why carry around three or four days’ worth of fuel? A gallon of gasoline weighs 6 pounds  and a gallon of diesel fuel weighs 7 pounds. Factor in the weight of the fuel tank, and carrying 50 extra gallons of fuel could mean needlessly hauling up to 400 pounds.

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. When used in the manufacture of truck bodies and van equipment, lightweight materials, such as thinner gauge high-strength steel, aluminum, fiberglass, and plastic composites, enable fleets to reduce vehicle weight to improve fuel economy, increase legal payload, and even drop down to a smaller (often more fuel-efficient) vehicle. Approximately 75%  of the average motor vehicle’s fuel consumption directly relates to factors associated with weight. In fact, for every 10% of weight eliminated from a vehicle’s total weight, fuel economy improves by 7%. Lowering vehicle weight is also a key enabler for reducing CO2 emissions.

The Quickest Way to Increase Fuel  Efficiency

Having drivers clean out vehicles is the quickest way to make vehicles more efficient and cut costs, but it is often low a fleet manager’s priority list. In our personal lives, we tend to procrastinate in decluttering our offices or homes, but, invariably, there is no better time to start than now. Encourage drivers to declutter vehicles in the same way as they would an annual spring cleaning.

Let me know what you think.

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About the author
Mike Antich

Mike Antich

Former Editor and Associate Publisher

Mike Antich covered fleet management and remarketing for more than 20 years and was inducted into the Fleet Hall of Fame in 2010 and the Global Fleet of Hal in 2022. He also won the Industry Icon Award, presented jointly by the IARA and NAAA industry associations.

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