IndyCar year in review: Looking back at the 2015 season

Chip Ganassi Racing driver Scott Dixon won his fourth Verizon IndyCar Series Championship in 2015.

Robert Laberge/Getty Images

RACE OF THE YEAR PART 1 – THE 99th INDIANAPOLIS 500

Graham Rahal celebrates after winning the Honda Indy 200 at Mid-Ohio Sports Car Course on Aug. 2, 2015 in Lexington, Ohio.

James Hinchcliffe gives the command to start engines before the Firestone 600 at Texas Motor Speedway on June 6, 2015 in Fort Worth, Texas.

Juan Pablo Montoya crosses the finish line to win the 99th running of the Indianapolis 500 mile race ahead of Will Power at the Indianapolis Motor Speedway on May 24, 2015.

Ryan Briscoe crashes during the MAVTV 500 race at the Auto Club Speedway on June 27, 2015 in Fontana, California.

Josef Newgarden had two victories during the 2015 season.