Hornish also won the 90th Indianapolis 500, passing rookie Marco Andretti on the final lap less than 500 feet (150 m) from the finish line.

Third would have been enough to catapult fourth-place finisher Castroneves to take the title, but he instead ended up two points behind Hornish and Wheldon.

The biggest change being the withdrawal of Chevrolet- and Toyota-powered cars from the series, leaving Honda as the only engine manufacturer.

However, Tony George and Patrick Dempsey's Vision Racing added a car for displaced Tomas Scheckter.

The Pikes Peak International Raceway was eliminated from the 2006 schedule as the track was sold by its owners and subsequently closed.

Hemelgarn Racing signed P. J. Chesson late in the offseason with backing from Carmelo Anthony to replace the outgoing Paul Dana.

There were also ongoing rumors during the offseason that Tony George and Champ Car principal Kevin Kalkhoven had been meeting and discussing a potential merger, or a new series that would re-unite open wheel racing in America.

The two men have admitted to meeting and enjoying each other's company in skiing and golf, and in separate March 2006 interviews with the Los Angeles Times admitted that they were in fact discussing the prospects of combining the two series [1] Following the 2005 season both Chevrolet and Toyota exited the series as Engine suppliers leaving Honda as the sole engine manufacturer in the sport.

O  Oval/Speedway R  Road course S  Street circuit This race held at Homestead-Miami Speedway was run on March 26 and covered by ABC.

Paul Dana was killed in the crash and teammates Danica Patrick and Buddy Rice withdrew from the race to honor his memory.

The race finished under the yellow flag after Tomas Scheckter and Buddy Rice hit the barrier with 4 laps to go.

Top ten results The Twin Ring Motegi, Japan race was run on April 22 and covered (via tape delay) by ESPN.

Hornish then went on to win the race, beating Marco Andretti in the second-closest finish in Indy 500 history.

Top ten results The Watkins Glen International race was run on June 4 and covered by ABC.

Dan Wheldon had led most of the race and looked in control only for a short delay on his final pit stop to drop him back to third.

Qualifying was rained out and Hélio Castroneves won the pole based on combined practice speeds.

The race finished in yellow flag at 4 laps to go due a blown tire from Hélio Castroneves which dropped him to 10th place.

Top ten results The Michigan International Speedway race was run on July 30 and covered by ABC.

Dan Wheldon won the race and tied Hornish in season points, but lost the title due to the tiebreaker (most wins).