Following more than a year of extensive collaboration with stakeholders throughout the industry, NASCAR finalized and delivered its 2015 racing package to teams yesterday.

Highlighted in the NASCAR Sprint Cup Series changes for 2015 are nearly 60 enhancements, including adjustments to the power train, aerodynamics and chassis that are designed to work in concert to deliver drivers more flexibility and teams more adjustability. Fans are expected to benefit from closer racing and more opportunities for drivers to pass on the track.

Among the changes are two that will affect the Sprint Cup Series' first road-course race of 2015 at the Toyota/Save Mart 350 at Sonoma Raceway, June 26-28. Most notably, the series has announced that it will work alongside Goodyear to introduce rain tires should conditions warrant during road-course events in 2015. Cup teams will be required to have wipers, a defogger and a rear flashing light installed in case of inclement weather. 

In addition, NASCAR will continue its popular group-qualifying procedure at all events in 2015, including the Daytona 500, with slight adjustments to the format. Road-course qualifying will consist of one 25-minute session, followed by a final 10-minute session.

"We have had fantastic racing so far in 2014," said Gene Stefanyshyn, NASCAR senior vice president of innovation and racing development. "We remain committed to constantly looking to improve it. Our fans deserve it and our industry is pushing for it. That will not stop with the 2015 package; the development will continue over many years to come."

NASCAR will institute a shorter rear spoiler in its 2015 NASCAR Sprint Cup Series package, which also includes a reduction of engine power, lower rear differential gear ratios and an optional driver adjustable track bar.

Additional changes for the 2015 rules include the elimination of team-facilitated private testing, with race teams being instead invited to participate in NASCAR/Goodyear tests throughout the season.

The NASCAR Sprint Cup Series returns to Northern California for the Toyota/Save Mart 350 at Sonoma Raceway, June 26-28. For more information or to reserve your tickets now, visit www.racesonona.com/nascar or call 800-870-RACE.