On October 31, 2005, it was announced that Team Penske ended their engine deal with Toyota which included Toyota's exit from IndyCar Series and reforged their historical full-works partnership with Honda with an initial five-year deal as Honda increased its IndyCar Series partnership role to exclusive global engine partner. Penske had collaborated with Honda engines in the 2000–2001 CART Champ Car season. After a prolonged period, the team announced Hélio Castroneves and Sam Hornish Jr. as their official race drivers. Despite Honda partnership, Penske had a "de facto" direct Honda factory support, with engines coming straight from the Japanese company's racing division in Japan and the United States including tune-up support from Ilmor Engineering in Plymouth, Michigan. The partnership started well in 2006, winning the 2006 Indianapolis 500 and 2006 IndyCar Series titles at the hands of Sam Hornish Jr..