Issue link: https://read.dmtmag.com/i/445385
FIRST CLASS l 13 flow around the vehicle, and with min- imal ground clearance, it helps keep air from the truck's underbody which is a major source of aerodynamic drag. "We want air moving around the vehi- cle, not into the underbody where it will be absorbed," says Smith. "And the ground clearance was something we experimented with on SuperTruck. We used to live with certain commitments to curb clearance and that we had to have a certain open angle from the contact edge of the tire to the tangent edge of the bumper. "But we took a new view of ground clearance here and brought the dam lower. Sure, we scraped one once in a while but bumper failure didn't occur nearly at the rate we imagined it would. So we made the bumper robust enough to absorb some contact, but easily replaceable as well. "And if a customer says, 'That ground clearance just isn't going to work for me,' they can get the package without the bumper dam." Also in the bumper and throughout the fairings, rubber closeouts — or fills in the much smaller gaps often found on a vehicle — help maximize aerodynamic performance. "We paid a lot of attention to sealing these gaps, and any additional leak paths or projected air flows," says Damon. "Once air enters the underbody it's just getting dragged along and that becomes a portion of the drag. It's all cumulative." Additional features Front tire wells also get special treat- ment with the EPIQ package. Tire wells are designed to accommodate a variety of tire sizes, but given that the EPIQ spec requires a specifically sized tire, a stylistically designed closeout provides a custom fit and minimiz- es drag-producing wheel well exposure. Additionally, the EPIQ spec employs an aerodynamically designed battery box, a single-horizontal exhaust position, the SmarTire Tire Pressure Monitoring System, low rolling resistance tires and optimized spec'ing software, which helps ensure most efficient rear axle ratios and engine settings for EPIQ customers. "We're always looking for opportuni- ties to improve fuel economy across the product line," says Sproull. "In this case, our experience with SuperTruck allowed us to bring these fuel-saving enhance- ments to our customers as quickly as possible." FC 3 BUMPER DAM Directs air away from vehicle underbody. 3 4 WHEEL CLOSEOUT Reduces aero drag, especially in cross- wind. 4 5 CHASSIS FAIRING Directs airflow off the drive tire. 5 2 2 CLOSEOUT Rubber fitted to small gap helps maximize aerody- namic performance. 6 6 6 EXTENDERS "Uncommonly long" extenders minimize cab- trailer gap.