Scott McLaughlin says he is still getting used to the massive forces which make IndyCar so different Supercars.
The Kiwi rookie had a brilliant weekend in Texas, finishing second to champion Scott Dixon in the first race and following that up with an eighth placing.
McLaughlin told Gold AM's morning host Brian Kelly he surprised himself by getting a podium finish in just his fourth IndyCar start, having started the race in 15th.
"I thought over time there would be a chance for it to happen, but for it to happen so early is really exciting," he said when asked about standing alongside his hero and fellow Kiwi Dixon.
"I'm really proud of the preparation we put in as a team, and myself in understanding the car and the track. That is what paid off in the end.
"We didn't have as much practice as we thought because of the rain … things went our way but we're very happy and surprised about being on the podium and proud of that as well.
"You need a fast car for one and I certainly had that. I was able to do things that other people weren't and make a couple of passes.
"The other thing is strategy – we had one that worked out nice. There was a yellow flag in the early part of the race and some people had pitted … we had stayed out and were able to start the next part of the race form seventh or eighth."
After finishing second in the first race, team boss Roger Penske gave McLaughlin a hug.
"He said 'well done', that he was really proud of me – then was straight back on it. He said 'let's go, there's another race'. He's a real professional, a great guy."
McLaughlin said the transition from Supercars, a sport he dominated in Australasia, to the IndyCar series was huge.
"The biggest thing is these cars are a lot lighter with a lot more down force," he said.
"Basically it is an upside-down plane – planes create lift, (IndyCar) create down force to keep the car on the ground. There are three or four more times down force (compared to Supercars).
"It is really hard to get used to … trusting that the car will stick to the road at these speeds is quite difficult. The shunts are also a lot bigger - the cars snap and they can go up in an instant."
He is now preparing for the two big May races at Indianapolis, the Grand Prix and the famous 500. The track is about an eight-hour drive from his home in Charlotte. McLaughlin will camp at the Indy track for nearly a month.
His car will hit speeds around 380kph on the oval track – the fastest he has raced "by a country mile".
"The main goal is to finish every lap, don't drop off the lead lap, which exactly what we did (in Texas)," McLaughlin said.
"To come away with second and eighth was even better, icing on the cake for us."