Issue link: https://read.dmtmag.com/i/445385
12 l FIRST CLASSCLASS "We took a kitchen-sink approach to SuperTruck," adds Ken Damon, the SuperTruck program manager and pres- ently in charge of Vehicle Performance Engineering Analysis. "We went in deter- mined to fix everything we knew that impeded the achievement of maximum fuel economy." The new EPIQ package figures to help push operators ever-closer to the elusive 10 mpg threshold in some applications. The package is designed specifically for the Model 579 and removes specification challenges for customers seeking to achieve maximum fuel economy, while still giving consideration to variables ranging from application nuances to driver performance. "So many factors go into the fuel economy equation," says Smith. "How you drive, idle time, the loads you haul. It's important that we understand the customer's business. Doing so allows us to be involved in predictive fuel econo- my analysis, not reactive fuel economy analysis. "It's a big difference, and the result is very advantageous to the customer on the front end of the ordering process." The EPIQ package offers detailed aero- dynamic refinements and other features, but the formula starts with an enhanced drivetrain, according to engineers. PACCAR MX-13, APEX The PACCAR MX-13 engine was an easy choice for the EPIQ package, accord- ing to Chief Engineer Landon Sproull. "The MX-13 was already an industry leader in fuel efficiency, performance and reliability, making it an optimum compo- nent of the EPIQ package," says Sproull. "The MX-13 delivers improved fuel econ- omy through electronically controlled fuel injection pumps and high-pressure rail technology." The MX-13's drivetrain partner is the Fuller Advantage Automated Transmission. The optimized pairing is designated as APEX and features precise communication between the engine and the transmission, as well as proprietary control logic to fur- ther enhance fuel economy. "This exclusive, enhanced drivetrain is developed to deliver fully integrated pow- ertrain performance and superior fuel efficiency," says Sproull. Complete Aerodynamic Package Reducing aerodynamic drag of a Class 8 tractor and trailer is in large part a matter of "sealing the gaps," according to engineers. And the biggest one is the trailer gap. "That's such a challenge because you can't get away from the need for some kind of gap back there for turning radi- us and swing clearance, but that gap hurts you in any kind of crosswind," says Smith. "Going straight, no wind, you're fine, but in a yaw condition with the truck off axis, that's when you're going to devel- op some drag." Engineering's response was 18-inch sleeper side extenders with 8-inch rubber flares and roof fairings with an exclusive rear wall closeout. The roof fairing has an arc-shaped cutout to provide maximum gap closure while still allowing necessary swing clearance for a standard dry van. "Our side extenders are uncommonly long, but that's the idea — to create a ball and socket where the nose of the trailer could fit up into the extenders and the bridge (roof) fairing," says Steve Polansky, Senior Project Engineer. "Air jumps the gap between the sleeper and trailer in this configuration, even in severe crosswinds." Full chassis fairings are designed to direct airflow around the trailer and off the drive tires. These are also flared toward the rear of the chassis. "The design there helps kick the air out so it flows around the trailer and drive tires," says Smith. "Plus it allows an easier step for the customer over the drive axle." A new bumper dam also directs air "We went in determined to fix everything we knew that impeded the achievement of maximum fuel economy." 1 1 BRIDGE Closes the cab- trailer gap; arc design allows swing clearance. g