Three days of testing began on Thursday, with the majority of the IndyCar paddock participating. Six teams took to the Indianapolis Motor Speedway road course, using the new hybrid system on the series’ 2.2-liter twin-turbocharged engine for the first time.

Tom Blomqvist (Meyer Shank Racing), Romain Grosjean (Juncos Hollinger Racing), Jack Harvey (Dale Coyne Racing), Graham Rahal (Rahal Letterman Lanigan Racing), Sting Ray Robb (AJ Foyt Racing), and Rinus VeeKay (Ed Carpenter Racing) combined to turn 400 laps on Thursday.

VeeKay was very pleased with how his day went. “It’s fairly similar,” he said. “There’s just a lot more buttons for me to press and a lot more stuff you need to go through.”

Rahal provided more context on the difference with the hybrid. “It’s a whole new ball of wax for me,” he said. “To understand how you do the hybrid regeneration, whether it’s automatic regen, braking regen, throttle regen manual, which is interesting because I think everybody will play it a little bit different. It’s an element that you we’re going to have to watch a lot. But I would say so far, so good.”

Graham continued to elaborate. “It’s not like push-to-pass where that’s limited. You will be limited on the lap just from a usage perspective because there’s only so many spots that you can get the deployment done, but also the regen side, you got to fill the battery back up before you use it. So, every brake zone, you’re trying to fill the Energy Storage System.”

“If you go too far though, it changes the brake bias in the car, and we’ll move the brake bias forward because it’s not utilizing any regen, so it’ll just move it forward four percent or lock up brakes and go crazy. So you’re trying to balance these numbers in your head on every straightaway, and we’ve got long straightaways here at IMS.”

The hybrid power unit will enhance the racing action with additional horsepower and further the series’ efforts to deliver the most competitive motorsport on the planet. The new 2.2-liter twin-turbocharged V-6 engine with hybrid technology will feature additional overtake options, ultimately giving drivers more choices and control – enhancing the on-track competition and excitement.

Team Penske, Chip Ganassi Racing, Andretti Global, and Arrow McLaren have all had ample time already with the hybrid unit. Now, all ten full-time teams have been able to test.

On Friday, the same six teams returned to test – all with different drivers. Agustin Canapino (Juncos), Santino Ferrucci (Foyt), Pietro Fittipaldi (RLL), Christian Rasmussen (ECR), Felix Rosenqvist (Meyer Shank), and Nolan Siegel (Coyne) all took their turn on the 2.439-mile road course.

Three more drivers joined the party on Friday, as Andretti took part in a team test. All three drivers (Colton Herta, Kyle Kirkwood, Marcus Ericsson) turned laps in their respective non-hybrid machines on Friday, in preparation for the May 11 GMR Grand Prix.

The final day of testing resumes tomorrow, with three teams and six drivers. Penske and ECR will have their full driver lineup to do some non-hybrid testing while Christian Lundgaard will be the lone driver testing the hybrid unit.

After this test wraps up, the next big item on the calendar is the two-day (April 10-11) Indianapolis 500 Open Test.