As Toyota confirmed defection from CART Champ Car to IRL IndyCar Series, the team switched to works Toyota engines from 2003 season onwards as it was announced on April 2, 2002. The team's partnership with Toyota engines started well in 2003 including winning the 2003 Indianapolis 500 in the hands of Gil de Ferran. However Team Penske's Toyota partnership started to decline in 2004 by scored only two wins, five pole positions and three fastest laps compared to 2003 due to driver errors and also incidents. The team also resurged slightly in 2005 with just only three wins and two pole positions.