The 2006 Indianapolis 500 (formally the 90th Indianapolis 500-Mile Race) was an IRL IndyCar Series open-wheel race held on Sunday, May 28, 2006, at the Indianapolis Motor Speedway in Speedway, Indiana, before approximately 250,000 spectators. It was the fourth race of the 2006 IRL IndyCar Series season, the 90th running of the event, and the ninth under Indy Racing League (IRL) sanctioning.

The month of May began with Rookie Orientations on May 7, and the track was opened to all competitors for practice two days later. Time trials were scheduled to be held on May 13–14 and May 20–21; however, the first two days were rained out, forcing IRL officials to push pole qualifying back to May 20. Sam Hornish Jr. of Team Penske quickly emerged as a pre-race favorite, setting quickest times in all but one practice session and earning the pole position. The last day of qualifying, Bump Day, saw a battle for the final starting position between Thiago Medeiros and Marty Roth. Medeiros took the position after Roth crashed with less than an hour left. The 30th annual Pit Stop Challenge was won by Hélio Castroneves' pit crew.

In the race, Wheldon first took the lead on the tenth lap and went on to lead a race-high 148 laps, relinquishing the lead during pit stop cycles. Hornish Jr. overtook Wheldon soon after a restart on lap 130, but Wheldon got by him 15 laps later. Hornish Jr. was then dropped to the rear of the field due to a pit stop blunder under a caution flag period. As part of a strategy to assume the lead late in the race, he and Michael Andretti made their final stops on the 160th lap. Meanwhile, during a battle for the lead with Tony Kanaan, Wheldon drifted up the track and his tire punctured. An unexpected pit stop cost him a shot at the victory.

A luckily-timed caution with under ten laps remaining helped Michael Andretti and Hornish Jr. move up to the front of the field along with 19-year-old rookie Marco Andretti, who pitted seconds before the caution. One lap after the restart, Marco Andretti passed his father, Michael, in the first corner. Hornish Jr. soon moved up to second place and made several attempts to pass Andretti. On the final lap, Hornish Jr. executed a slingshot pass to the left side of Andretti with about from the finish line to take his sole Indianapolis 500 win and Roger Penske's record-extending 14th win as a car owner in the event. It was the first time in Indianapolis 500 history that a driver completed a pass on the last lap for the win, and the margin of victory — 0.0635 seconds — was the second-closest in the race's history at the time, and the fourth-closest finish as of 2026. Despite Andretti's loss, he was unanimously named Rookie of the Year.

Hornish Jr. went on to win his third (and final) Drivers' Championship in the IndyCar Series later that season, becoming the second consecutive driver to accomplish the feat. Tom Carnegie, who had commentated the Indianapolis 500 every year since 1946, announced his retirement from being Indianapolis Motor Speedway's public address announcer weeks after this race.

Race background

The Indianapolis 500, commonly shortened to the Indy 500, is an annual race held at the Indianapolis Motor Speedway, a four-turn, asphalt oval circuit, in Speedway, Indiana, United States. The event is contested by "Indy cars", a formula of professional-level, single-seat, open cockpit, open-wheel, purpose-built race cars. Since its inaugural running in 1911, the Indianapolis 500 has become a staple of Memorial Day weekend and one of, if not the, most prestigious races in motorsports. Dan Wheldon was the defending race winner.

Chevrolet and Toyota both announced their withdrawals from the IndyCar Series after the 2005 season, leaving Honda as the sole engine provider for all teams for 2006 and beyond. IndyCar's single-engine program allowed costs to be reduced for teams who were looking to buy or lease an engine. It marked the first time since 1960 that every entry in the Indianapolis 500 would be fielded with the same engine.

A new series initiative introduced the use of ethanol fuel. As part of a two-year roll-out, all entries for 2006 were required to utilize a 10% ethanol and 90% methanol fuel blend (E10). While this was the first time all entries in the Indianapolis 500 utilized ethanol fuel, it was not the first time that ethanol was used during the race. Leon Duray's Miller car was fueled by ethyl alcohols in 1927, and Art Sparks claimed to have used ethanol in his cars in 1937–1939.

The final hour of each practice and qualifying session for the Indianapolis 500 was known as "Happy Hour" because the cooler track temperatures, caused by the sun setting behind the front-stretch grandstands, produced significantly faster speeds. As a result, many teams would scramble to put down the fastest lap of the session before time expired. However, a month prior to the 2006 Indianapolis 500, Indiana began using daylight saving time for the first time in over 30 years, inadvertently ending the "Happy Hour" tradition.

2006 IndyCar Series

The Indianapolis 500 was the fourth round of the 2006 IndyCar Series season. Marlboro Team Penske driver Hélio Castroneves entered the event with the Drivers' Championship lead, having earned 146 points and two wins in the first three races of the season. Wheldon trailed Castroneves by 42 points. Sam Hornish Jr. earned 94 points and placed third in the standings. Scott Dixon, with 92 points, and Tony Kanaan, with 89 points, took the fourth and fifth positions, respectively.

Race schedule Race schedule — May 2006SunMonTueWedThuFriSat   1  2  3  4  5  6Mini-Marathon 7 8 9Practice10Practice11Practice12PracticeFast Friday13Time Trials14Time Trials15 16 17Practice18Practice19Practice20Pole Day21Bump Day22 23 24Community Day25Indy Pro Series Time Trials26Carb DayFreedom 10027Parade28Indianapolis 50029Memorial Day30 31    Source: Color Notes Green Practice Dark blue Time trials Silver Race day Red Rained out* Blank No track activity * Includes days where track activitywas significantly limited due to rain

Entry list

The official entry list for the 2006 Indianapolis 500 was released on April 13, 2006. Entry invitations were mailed to eligible race teams on February 22, and the deadline was set on April 5. Sixty-six cars for 38 entries were featured on the entry list, with 26 drivers being named to the entries. By May 7, the entry list had been updated, with 31 car-driver combinations being announced. Among the drivers entered were six former winners of the race and three race rookies. Each car used Honda Indy V8 engines and Firestone tires. Dallara and Panoz were the chassis providers.

Team and driver changes The biggest storyline heading into the Indianapolis 500 revolved around Dan Wheldon, who opted to drive for Target Chip Ganassi Racing in 2006, despite winning the Indianapolis 500 and the IndyCar Series championship with Andretti Green Racing the previous season. Replacing him in the 26 entry would be third-generation driver Marco Andretti, who was one of the three race rookies. Andretti's father, Michael Andretti, announced his comeback from retirement to compete in the Indianapolis 500 alongside his son, driving the one-off 1 entry for Andretti Green Racing.

Similarly, 1998 Indianapolis 500 winner Eddie Cheever made his return to the IndyCar Series and the Indianapolis 500 for the first time since 2002. During his hiatus, Cheever exclusively focused his efforts on his ownership role at Cheever Racing. Two-time Indianapolis 500 winner Al Unser Jr. also came out of retirement and returned to the Indianapolis 500. He was teamed with 1996 winner Buddy Lazier in the Dreyer & Reinbold Racing-prepared 31 car.

On March 23, Rahal Letterman Racing filed three entries for the Indianapolis 500, which were to be driven by 2004 race winner Buddy Rice, 2005 Rookie of the Year driver Danica Patrick, and series rookie Paul Dana. However, after Dana was killed in a practice crash at Homestead–Miami Speedway on March 26, team co-owner Bobby Rahal selected seven-time Indy Pro Series winner Jeff Simmons to drive Dana's 17 entry for the remainder of the season, including the Indianapolis 500.

Testing and Rookie Orientation The Rookie Orientation and Refresher Programs, the latter of which were for drivers who did not race in the previous Indianapolis 500, took place at Indianapolis on May 7 and May 8, with ten drivers partaking in the test sessions. Rookie Orientation consists of four phases; the first phase features speeds between , the second phase features speeds between , the third phase features speeds between , and the fourth phase features speeds above . The rookie drivers had to pass all four phases in order to be eligible to race in the Indianapolis 500.

Testing – October 2005 On October 6 and October 7, 2005, a test was conducted at Indianapolis to evaluate Firestone tires. Castroneves, Wheldon, and Rice, all of whom were past Indianapolis 500 winners, were the lone participants. No incidents were reported, and all three drivers were happy with the test.

Open test – Wednesday April 5

An open testing session was held on April 5, 2006, in order to assess the efficiency of the Honda engines. Seventeen drivers participated in this open test session, which started 42 minutes late due to cool track temperatures. As a result of the late start, the session was extended by an hour and finished at 5:00 PM (UTC−04:00). Dixon was fastest in the session with a speed of . A total of 1,404 laps were completed by the seventeen drivers without incident. Lazier and Dreyer & Reinbold Racing were scheduled to take part in this testing session, but withdrew after one of their cars suffered an electrical fire at Homestead.

+ Top Speeds Driver Team Chassis 19 Scott DixonTarget Chip Ganassi RacingDallara 26 Sam Hornish Jr.Marlboro Team PenskeDallara 310 Dan WheldonTarget Chip Ganassi RacingDallara Source:

Opening Day and Rookie Orientation – Sunday May 7

May 7, the opening day for the Indianapolis 500, began with a celebration of the Andretti family. Mario, Michael, and Marco Andretti completed a three-wide ceremonial lap around Indianapolis, with Mario driving the same car with which he won the pole position for the 1967 Indianapolis 500. At 12:10 PM local time, Marco Andretti became the first driver to complete a lap on opening day, and passed the Rookie Orientation along with P. J. Chesson. Michael Andretti, Unser Jr., Arie Luyendyk Jr., and Townsend Bell participated on the first day of refresher testing, with Andretti setting the fastest lap of the day at a speed of and easily passing his test. Four caution flags were thrown during the session, three of which were for debris and one for a mechanical issue involving Bell, who stopped his car at the entrance of pit lane.

+ Top Speeds Driver Team Chassis 11 Michael AndrettiAndretti Green RacingDallara 226 Marco Andretti Andretti Green RacingDallara 391 P. J. Chesson Hemelgarn RacingDallara Source:

Rookie Orientation – Monday May 8

On May 8, the second day of Rookie Orientation, eight drivers took to the track under sunny conditions. Bell set the fastest lap of the five-hour, incident-free session with a lap of . He and Thiago Medeiros passed the rookie test, while Luyendyk Jr., Larry Foyt, and Unser Jr. all passed the refresher test. With an hour remaining in the session, Michael Andretti lent his son his 1 Honda for a handful of laps around the circuit because of complaints that Marco had about his own 26 Honda regarding grip.

+ Top Speeds Driver Team Chassis 190 Townsend Bell Vision RacingDallara 21 Michael AndrettiAndretti Green RacingDallara 31 Marco Andretti Andretti Green RacingDallara Source:

Practice – Week 1

Tuesday May 9