Graham Rahal and his IndyCar peers are still getting a clear handle on performance changes in cars featuring new aerodynamic kits.

The looks for the cars from manufacturers Chevrolet and Honda are pretty distinctive.

Drivers took to the track at Barber Motorsports Park Monday to start two days of testing and learning ahead of the upcoming season, which begins March 29 in St. Petersburg, Florida.

Honda and Chevrolet cars sport noticeably different designs on parts stretching from Chevy's vented rear wings to Honda's laddered front wings.

Says Rahal: "The aero kits will certainly be different and people will definitely notice it."

There are performance differences and physical challenges, too. Drivers Josef Newgarden and Rahal both said their necks are sorer when they're done on the track.