CONCORD, N.C. - Robby Gordon accused Danica Patrick of having an unfair advantage in the Indianapolis 500 and said Saturday he will not compete in the race again unless the field is equalized.

Gordon, a former open-wheel driver now in NASCAR, contends that Patrick is at an advantage over the rest of the competitors because she only weighs 100 pounds. Because all the cars weigh the same, Patrick’s is lighter on the race track.

“The lighter the car, the faster it goes,” Gordon said. “Do the math. Put her in the car at her weight, then put me or Tony Stewart in the car at 200 pounds and our car is at least 100 pounds heavier.

“I won’t race against her until the IRL does something to take that advantage away.”

The Indy Racing League does not consider the weight of the driver in its race specifications. The car has to weigh at least 1,525 pounds before the fuel and driver are added, and teams in Indy have estimated that Patrick will gain close to 1 mph in speed because of her small stature.

Although her rivals in Sunday’s race have said she doesn’t have a huge advantage, pole-sitter Tony Kanaan told reporters he would like the Indy Racing League to look into the issue.

“Right off the bat, a guy my size is spotting her 105 pounds,” Gordon said. “That’s the reason she’s so much faster.”

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Gordon never planned to race in the Indy 500 this season, choosing instead to focus on his job as owner of a NASCAR team. Gordon had run in the 500 and NASCAR’s Coca-Cola 600 on the same day the past four years.

But with his startup team struggling, Gordon couldn’t afford to take his focus off NASCAR. He qualified 25th for Sunday’s race, but his car was among the fastest in most of the practice sessions.

Still, he said the No. 7 Chevrolet is searching for more horsepower from its Menard-built engines.

“We are a long ways away,” Gordon said. “But we’re still working and we will get there.”