The WeatherTech Championship's revised class structure has led to updated sporting regulations for 2019.
Following two full seasons in IndyCar, Ed Jones will join Ed Carpenter Racing as the driver of the No. 20 Chevrolet on road and street circuits.
A fierce battle in GTLM culminated in victory for Porsche at the 21st annual Motul Petit Le Mans.
Championship-leading team Action Express Racing swept the top of the Practice 1 timesheet at Road Atlanta while the hopeful CORE autosport placed sixth.
After taking turns winning the Freedom 100 and Indy Lights championship, Colton Herta and Pato O'Ward will compete with Harding Steinbrenner Racing in 2019.
Only A.J. Foyt owns more Indy car championships than Scott Dixon.
Before 2018, Will Power had never started outside the top five at Sonoma Raceway.
Aiming to win the season finale despite not being in championship contention, Ryan Hunter-Reay put his DHL Honda on the pole at Sonoma.
Josef Newgarden led a trio of Chevrolets in the top five of Practice 2 at Sonoma, including rookie Patricio O'Ward who was third fastest.
Even with his 29-point lead, Scott Dixon has to be careful to keep Alexander Rossi behind him during the final race of 2018.