May 12 practice results || Combined practice results

The expected gain in miles per hour from the superspeedway aerodynamic bodywork components on the Verizon IndyCar Series cars is becoming more evident with each practice day for the 99th Running of the Indianapolis 500 Mile Race. 

Three-time 500 champion Helio Castroneves showed he can go fast with and without a "tow" using the new aero kits. Castroneves posted the fastest overall lap as well as the best lap without the aid of cars cutting the air in front of him in the third practice session on the Indianapolis Motor Speedway oval.

Driving the No. 3 Shell V-Power Nitro+ Team Penske Chevrolet, Castroneves clocked the quickest overall lap of 227.514 mph less than an hour into day. He returned in the closing 60 minutes, known as "Happy Hour," to run a lap of 225.315 without a tow from cars in front.

Aero kits were introduced this season to Verizon IndyCar Series competition from manufacturers Chevrolet and Honda, and have helped set track records most everywhere the series has run in 2015. The Indianapolis 500 marks the first time the superspeedway kits have been in use, but their advantage is plain. Castroneves' fast lap today, in just the third practice session, is already better than any lap posted through the first five sessions a year ago. And speeds are known to increase as the practice week progresses.

Castroneves, currently third in the championship standings behind teammates Juan Pablo Montoya and Will Power, said there is still work to be done that could achieve even more speedy dividends.

"It was a good day," Castroneves said. "The Shell V-Power Nitro+ car was super strong, super solid, felt comfortable. Now we've got to just keep working with this new aero kit. Today was basically the second day that we've been working constantly, but I like what I see. 

"Things are looking in the right direction. We're not focused on just the lap, we're focused on the performance of it all."

Castroneves' third Penske teammate, Simon Pagenaud, was second fastest overall at 227.382 mph in the No. 22 Avaya Team Penske Chevrolet, followed by Scott Dixon at 226.769 mph in the No. 9 Target Chip Ganassi Racing Chevrolet.

Justin Wilson, driving his second race for Andretti Autosport, was fourth overall and the quick Honda at 226.688, but his engine appeared to let go on the frontstretch of the 2.5-mile oval, putting an end to the six-hour session a few minutes early.

"I looked in the mirror and there was a lot of smoke coming out of the exhaust so, yeah, it's unfortunate," Wilson said. "I don't know any more than that right now. But looking back over the day, I think we've had a pretty good day. The car's been quick. We tried a couple of different setups that the team's got going on. Both feel pretty good and quick."

Practice resumes May 13-15. Two days of qualifying May 16-17 will set the 33-car grid for the "Greatest Spectacle in Racing." After that, all that's left before the May 24 race is afternoon practice on May 18 and the traditional Carb Day one-hour practice on May 22.