<P> The inaugural race was held in 1911 and was won by Ray Harroun . The event celebrated its 100th anniversary in 2011, and the 100th running was held in 2016 . Takuma Sato is the current champion . The most successful drivers are A.J. Foyt, Al Unser, and Rick Mears, each of whom have won the race four times . The active driver with the most victories is Hélio Castroneves, with three . Rick Mears holds the record for most career pole positions with six . The most successful car owner is Roger Penske, owner of Team Penske, which has 16 total wins and 17 poles . </P> <P> The Indianapolis 500 is held annually at the Indianapolis Motor Speedway, a 2.5 - mile oval circuit . Drivers race 200 laps, counter-clockwise around the circuit, for a distance of 500 miles . Since its inception in 1911, the race has always been scheduled on or around Memorial Day . Since 1974, the race has been scheduled for the Sunday of Memorial Day weekend . Practice and time trials are held in the two weeks leading up to the race . </P> <P> Traditionally, the field consists of 33 starters, aligned in a starting grid of eleven rows of three cars apiece . The event is contested by "Indy cars", a formula of professional - level, single - seat, open cockpit, open - wheel, purpose - built race cars . As of 2015, all entrants utilize 2.2 L V6, twin - turbocharged engines, tuned to produce a range of 550--700 horsepower (410--520 kW). Chevrolet and Honda are the current engine manufacturers involved in the sport . Firestone, which has a deep history in the sport, dating back to the first 500, is the exclusive tire provider . </P> <P> The race is the most prestigious event of the IndyCar calendar, and one of the oldest and most important automobile races . It has been avouched to be the largest single - day sporting event in the entire world . Likewise, the Indianapolis Motor Speedway itself is regarded as the world's largest sporting facility in terms of capacity . The total purse exceeded $13 million in 2011, with over $2.5 million awarded to the winner, making it one of the richest cash prize funds in sports . </P>

What kind of cars race in the indy 500