Not too long ago, the D&D Sexton Inc. fleet was averaging 5.5 MPG, notes Dean Sexton, president of the Carthage, Mo.-based refrigerated carrier. “Today,” he says, “our average is approaching 7 MPG, and we have some vehicles and drivers that are getting 8 MPG on a consistent basis.”
Sexton credits a number of equipment and specification initiatives for the improvement in fuel economy at the company he established in 1981 and has seen grow from a single truck into a 48-state carrier with 155 tractors and 350 refrigerated trailers. “We continually research and implement innovative, environmentally responsible solutions that reduce idle time and save fuel,” he says.
One of the latest moves made by D&D Sexton was to specify 40 Freightliner Cascadia Evolution tractors. “We waited for these models to become available before placing an order,” Sexton relates. “After evaluating their design and specifications, we became convinced that the Evolution’s aerodynamic enhancements will provide the 5% improvement in fuel economy over our current Cascadia models that the manufacturer claims.”
D&D Sexton also closely evaluated APUs before deciding to outfit its fleet with Thermo King TriPac Hybrid Idle Reduction and Temperature Management Systems. “We put off that decision for a long time because we had some early experience with on-board generators years ago that left us with a negative impression,” Sexton states. “As fuel prices continued to climb, however, we knew it was time to look at the latest APU technologies.”
Currently, there are 23 late model D&D Sexton tractors that have been retrofitted with TriPac units by Thermo King’s Springfield, Mo., dealer. All 40 of the new Cascadia Evolution tractors that will join the fleet will be equipped with the APUs, as well.
Fuel savings
“We trade tractors every four years,” Sexton relates, “so it will take another year or two before the entire fleet has TriPac units. On the vehicles we have already outfitted, though, we’ve seen engine idle time drop from as high as 50% to less than 10%. Burning about two-tenths of a gallon per hour compared to one gallon per hour at idle, the APUs will pay for themselves very quickly in fuel savings alone.”
Ed Boes, terminal manager at D&D Sexton, who works closely with Dean Sexton on specs, points to several other fuel saving choices that have been adopted. “Our new tractors are spec’d with Eaton UltraShift Plus automated two-pedal transmissions,” he relates. “Over the years, we changed our specs from overdrive transmissions to direct drive models coupled with faster axle ratios. We now believe the UltraShift Plus will help us further improve fuel efficiency. We’re also specifying Cummins engines on new tractors to evaluate this drivetrain combination.”
D&D Sexton, Boes says, is equally focused on fuel saving trailer technologies. Standard on Utility reefers, the fleet has been spec’ing Thermo King SB-230 SR refrigeration units. “We handle everything, including deep frozen loads, so the Thermo King unit’s OptiSet features give us the flexibility of continuous run and modulated temperature settings for improved efficiency,” he states. “Additionally, we’re using Thermo King TracKing temperature management systems to ensure proper temperature settings and save as much as 15% in reefer fuel costs.”
The web-based TracKing solution provides D&D Sexton with the ability to remotely monitor and track refrigeration units. Door switches connected to the system can uncover frequent openings, identifying an opportunity to reduce fuel costs, and fuel sensors enable accurate fuel consumption monitoring.
Positive improvement
D&D Sexton also is improving fuel economy by installing trailer tails and side skirts on its fleet. Included are Green Wing side skirts from Ridge Corp. and TrailerTails supplied by ATDynamics. “We’re retrofitting trailers in our shop,” Boes says, “and have finished about 80% of the fleet. So far, we’re already seeing a positive fuel economy improvement compared to trailers without the aerodynamic devices.”
| D&D Sexton Tractor Specifications Model: Freightliner Cascadia XT Wheelbase: 225 in. Engine: Detroit DD15; 455 HP, 1650 lb./ft. Clutch: Eaton SOLO Advantage; 15.5-inch, self-adjusting Transmission: Eaton Fuller FR-15210B Direct Drive Driveshafts: Meritor RPL25, RPL20 Front Axle: Detroit, 12,000-lb. Front Suspension: Freightliner Power Steering: TRW THP-60 Rear Axle: Meritor MT-40-14X Dual Trac; 40,000-lb., 2.47 ratio Rear Suspension: Freightliner Airliner Wheel Seals: SKF Scotseal Plus XL Brakes: Bendix ADB-22X-V Air Disc ABS: Meritor WABCO 6S/6M, Traction Control and Roll Stability Parking Brakes: Bendix Wheels: Alcoa LVL ONE aluminum, Dura-Bright finish Tires: Michelin; 275/80R22.5 XZA3+ steer, 445/50R22.5 X One XDA Energy drive 5th Wheel: Fontaine 7000 Series No-Slack II Air Compressor: Bendix BA-921, 19.0 CFM Air Dryer: Bendix AD-IP, heated Fan Clutch: Kysor K-30 on/off Batteries: Alliance 7T31 Group 31 Starter: Delco 39MT+ HD/OCP Alternator: Delco 36SI, 160 amp Block Heater: Phillips-Temro, 1,500 watt Lighting: LED Seats: National Premium; high back, air suspension Fuel Tanks: dual aluminum 125-gal. Paint: Dupont Red Metallic Elite |
Fuel savings at D&D Sexton also are being realized from a change to wide base single tires. “We switched to Michelin X One singles from duals on drive axles several years ago to save fuel, and we’ve now converted about half of the trailer fleet,” Boes reports. “What we’ve found is that while we give up a little bit of tread life compared to duals, we make up for it in fuel cost savings.
“We’re actually in the process of testing three different wide base single tires on trailers to evaluate tread wear,” Boes continues. “At the same time, we are looking at these tires as a weight saving specification. With the addition of APUs on tractors, which add 450 to 500 lbs., and the heavier weight of newer engines and emissions systems, weight has become an issue.”
Boes goes on to relate how D&D Sexton is cutting weight from its tractors in other ways. For instance, wheelbases have been shortened by three inches—which also provides an aerodynamic improvement by closing the tractor-trailer gap—and dual 100-gal. fuel tanks have been spec’ed on Cascadia Evolution tractors.
“With that change,” Boes adds, “we cut tank weight and the weight of 50 gal. of fuel. However, we only made the change after determining that carrying less fuel would not be a concern for drivers over our fueling network.”
Another weight-related issue has been addressed at D&D Sexton by equipping trailers with Air-Weigh LoadMaxx Series on-board trailer scales. “We’ve found these scales to be worth the investment,” Boes states. “They allow drivers to check axle weights immediately after loading and, if necessary, move the trailer tandems to scale legally without having to travel to scale house and risk being overloaded.”
| D&D Sexton Trailer Specifications Model: Utility 3000R Reefer Length: 53 ft. Refrigeration Unit: Thermo King SB-230 SR Landing Gear: Jost Magnum 441 Axles: Meritor Suspension: Meritor Ride Sentry Oil Seals: SKF Scotseal Plus XL Brakes: Bendix ADB-22X-V Air Disc ABS: Bendix 4S/2M, Roll Stability Tires: Michelin 445/50R22.5 X One XTA Wheels: Alcoa LVL ONE aluminum, Dura-Bright finish Lighting & Electrical: Grote LED lamps; Phillips harness |
Enhancing safety
Measuring return on investment in all kinds of technologies is important, notes Dean Sexton. For example, the company has seen safety improvements with Bendix air disc brakes added recently, and with Meritor Roll Stability Support (RSS) systems it has spec’ed for the past five years. In addition, new tractors are fitted with Meritor WABCO OnGuard collision safety systems with active braking to assist drivers in maintaining safe following distances.
“Highway safety has always been one of our highest priorities,” Sexton says. “In that area and others, we also feel that our commitment to state-of-the art solutions has helped reduce our driver turnover to 40%, well below the industry average. Many of our drivers have been with us for more than 20 years.”
D&D Sexton has received numerous safety awards over the years. Recently, Thermo King recognized the carrier for its commitment to energy efficiency and sustainability with the manufacturer’s Energy Efficiency Leader Award.
“We have routinely adopted new technologies and are continually focusing on innovative solutions that meet our fuel and operational efficiency needs,” Sexton concludes.
