The sanctioning body said the rules were formulated with the goals of enriched competition, improved safety, reduced cost, enhanced product relevance and environmental (green) improvements in mind.
Most notable on the list of changes are a NASCAR-mandated ban on all team-initiated private testing, along with the deletion of NASCAR Preseason Thunder testing at Daytona International Speedway. Teams will still be invited to participate in periodic NASCAR and Goodyear tire tests, but will no longer be allowed to test on their own, regardless of venue.
Qualifying formats have been updated for all tracks. On short and intermediate tracks, qualifying will consist of three rounds: 15 minutes, 10 minutes and five minutes, with short breaks between rounds.
On superspeedways, the field will be split in “A” and “B” qualifying groups, with each group receiving a pair of five-minute qualifying rounds, with breaks between rounds. For the first time in history, the season-opening Daytona 500 will also feature a group qualifying format.
On road courses, qualifying will consist of two rounds: 25 minutes and 10 minutes, with a break between rounds.
Changes to the 2015 NASCAR Sprint Cup Series rules package include:
§ Reduction of horsepower to 725 via tapered spacer.
§ Roller valve lifters to replace flat valve lifter.
§ Lower rear differential gear ratios targeting 9,000 RPM.
§ Rear spoiler adjustment from 7.25 inches to 6 inches.
§ Optional driver adjustable track bar.
§ 38-inch wide radiator pan.
§ 50-pound reduction in minimum vehicle weight from 3,300 to 3,250 pounds (w/o driver) via ballast reduction.
In addition, rain tires will be utilized when necessary in NASCAR Sprint Cup Series road course events, along with mandatory windshield wipers, defogger and rear flashing rain light. These changes bring the series in line with the NASCAR Xfinity Series and NASCAR Camping World Truck Series.
New officiating processes for 2015 include a data log and capture system for pre-race inspections, along with automated pit road officiating at race events
NASCAR also announced newly approved brake calipers for 2015, as well as a new parts approval process. The sanctioning body will also offer an electronic rule book next season.