Focusing on how carriers can reduce their costs, we have a great guest contribution from Charles Intrieri. Charles founded and serves as the principal consultant for Charles M. Intrieri Consulting. Focusing on supply chain management, international purchasing, third party logistics implementation, and distribution with his consultancy, Chuck’s blog today highlights how fleets can reduce their fuel costs.
Trucking fleets face a variety of challenges, but those that best manage fuel consumption enjoy a competitive advantage over the rest.
According to the American Trucking Research Institute (ATRI), fuel costs account for roughly 35 percent of average marginal costs per mile. With diesel prices on the rise, a competitive advantage will be bestowed upon trucking companies who are best able to manage fuel consumption and contain fuel costs.
Ways To Improve Fuel Consumption:
Overall, aerodynamics accounts for 15 percent to 22 percent of the energy losses for a fully loaded Class 8 truck traveling at highway speeds. By matching cab height to trailer height, reducing the gap between the cab and the trailer, and installing fairings on the chassis and the trailer, truckers can realize significant fuel savings.
In addition, rounding the corners on trailers, installing wheel covers, removing sun visors and auxiliary mirrors, and installing aerodynamic primary mirrors or rear facing video cameras can lead to additional savings.
Rolling resistance accounts for another 13 percent to 16 percent of the energy losses for the average Class 8 truck travelling at highway speeds (and 8 percent to 12 percent of the energy losses for trucks operating in the city). These losses provide a clue as to why nearly all fuel tanker trucks and trailers are equipped with super-single tires instead of the standard dual variety.
Super-single tires reduce total vehicle weight by 1,000 pounds or more when paired with aluminum wheels. In cases where the truck is not cubed-out, as is the case with tanker trucks, these weight savings allow for higher payloads. They also generate significant improvements in fuel consumption per ton-mile.
According to statistics published in the Transportation Energy Data Book, the average fuel economy for dual-wheel tractor-trailer combinations was 6.73 miles per gallon in 2011. The fuel economy for super-single wheel tractor-trailer combinations was 7.35 miles per gallon. This equates to 9.2 percent savings, or more than 1,500 gallons per 125,000 miles—which is the average number of miles driven per truck per year. At $4 per gallon, that equates to $5,000 in savings per 100,000 miles, or $600,000 per year for a fleet of 100 trucks.
Fuel savings are not restricted to reducing rolling resistance or increasing aerodynamics, however. According to Brian Daniels, the powertrain products manager for Daimler Trucks of North America, drivers are directly responsible for 30 percent of the factors that affect fuel economy. So the message is clear for fleet managers – reducing fuel costs requires an investment in both equipment and driver training.
Chief among the fuel efficiency recommendations for drivers is to reduce highway speeds. The amount of horsepower required to overcome wind resistance increases 50 percent, from 120 HP to 180 HP, as a fully loaded Class 8 truck increases its speed from 60 mph to 70 mph.
Drivers should focus on maintaining a steady speed and low RPMs, as it’s more efficient to take advantage of torque down low rather than horsepower up high. There is, of course, an exception to the rule of maintaining steady engine speed, and that is to “drive with momentum” on undulating terrain. In anticipation of upcoming hills, drivers should accelerate gently, but then allow the truck to decelerate on the incline. Then, on the backside of the hill, truckers should use gravity to their advantage to re-gain speed.
In addition, fuel efficiency can be improved by reducing idling times. On average, 5 percent of fuel consumed by Class 8 trucks is burned while idling. Of course idling cannot be completely eliminated, but it can certainly be reduced. Driver incentive programs or driver pledges are one way to reduce idling. Fleets can also use automatic idle shutdown technology that turns off the engine after a set period of time idling.
Using these methods to improve fuel efficiency, fleets can reduce fuel costs, thus gaining a competitive advantage.