Under NASCAR's age requirement rules for the Truck Series, the 17-year-old Custer ran 10 races, all at tracks under in length (and Gateway Motorsports Park), with the team planning a full-time run in 2016 for the championship. Kasey Kahne, Kevin Harvick, Kyle Larson, Alex Bowman, and Jeb Burton also ran races in the No. 00 truck. The No. 00 ran 15 races, winning twice: with Kahne at Charlotte in May, and with Custer at Gateway in June. In 2016, Custer won the pole at Canadian Tire Motorsports Park, and looked to be the truck to beat. After leading the most laps, it seemed as though Custer would score his first win of the season and a spot in the inaugural chase, until John Hunter Nemechek put Custer into the grass and into the fence to win the race. After the race, Custer tackled Nemechek to the ground and was soon separated by NASCAR officials. No fines or penalties would be handed out to either driver.