Penske's performance in 2004 saw Castroneves being viewed as an outsider for the 2005 title. He began the season with a fifth place in the Toyota Indy 300 and a second at the following XM Satellite Radio 200. Starting the Indianapolis 500 from fifth position, Castroneves finished the race four places lower in ninth. At Richmond for the SunTrust Indy Challenge two races later, he qualified second and led a race-high 112 laps to win. The relationship between Castroneves and his teammate Hornish cooled after failed overtakes causing both drivers to collide. He qualified on the pole position at Pikes Peak International Raceway and Watkins Glen International and took six top-tens in the final ten races, finishing with 440 points for sixth in the drivers' championship.