Andretti hopes to keep momentum

Andretti, who has struggled to make an impression as of late, led 58 laps of the third race of the season last Sunday, going on to finish in fifth place.

It was his best result on a road course since finishing fifth at Watkins Glen last year.

Now the young American is hoping to keep his momentum going.

"We just have to keep marching forward," said Andretti, who scored his maiden IndyCar win in 2006.

"The four of us are working together to keep improving our race cars; we're still a bit off pace. Overall I think this shows we're on the right track."

He admitted he was pleased with his result at Barber, despite his strategy costing him a potential victory.

"We have to be happy to put the Venom car into the top five, especially after our finishes on road courses last year," he added.

"I think maybe we could have stretched out each of our stints a bit longer and gained on fuel one lap at a time. Helio [Castroneves] just went longer than us each time and that was the difference at the end. He was able to go that much further and we fell short."

Race winner Helio Castroneves praised Andretti after his drive, which the Brazilian reckons was typical of his father Michael.

"[Marco's] driving reminded me of his father, Michael Andretti," Castroneves said. "Marco did a good job in passing me [for the lead]. In fact, he kind of like pushed me away. And he was driving like he was more patient this time."