NASCCAR made significant rule changes for the Sprint Cup cars this season, including lower horsepower and modifications to the cars' aerodynamic package. The horsepower was reduced from 850 to 725 through a tapered spacer, which is an engine part used in the Xfinity and Camping World Truck Series. Revisions to the aero package include: rear spoiler adjustments to 6 inches high (2014 height: 8 inches) and minimum vehicle weight drops 50 lbs. via ballast reduction (2014 weight: 3,300 lbs. without driver).