As Auto-Racing Betting fans gear up for this weekend’s 92nd Indianapolis 500, they’d be wise to do some line shopping, as odds for the big race vary greatly at online sportsbooks.

Pole-sitter and 2007 runner-up Scott Dixon is the favorite to win "The Greatest Spectacle in Racing," but a winning wager would produce different payouts at various books.

One of the best lines for Dixon is 3-1 at Sportsbook.com. Dixon is +265 at SBG Global, and +220 at Sportbet.

Odds for other top drivers are even more diverse at the three sportsbooks.

Dan Wheldon, Dixon’s Chip Ganassi Racing teammate, is 9-2 at Sportbook.com, but +350 at SBG Global and just +260 at Sportbet.

SBG Global has a slightly better price for IndyCar Series points leader and two-time Indy 500 winner Helio Castroneves, at +475, compared to Sportsbook.com’s 9-2 and Sportbet’s +350.

But the most dramatic difference in odds is with Ryan Briscoe, who’ll start from the third position. The Australian is +800 at Sportbet, 12-1 at Sportsbook.com, and a whopping +650 at SBG Global.

Dixon is second to points leader Helio Castroneves in the points standings.

Last year, Dario Franchitti took the checkered flag under caution as he defeated Dixon to capture the win. Franchitti will not be racing on Sunday.

The Indianapolis 500 takes places Sunday at the Indianapolis Motor Speedway in Speedway, Indiana (Noon ET, ABC).

The Indy 500 is one of the oldest motorsport events, and is considered one of the three most significant motor racing events in the world, with one of the largest attendances, and radio and television audiences, of any single-day sporting event worldwide.