Nico Hulkenberg was encouraged by the new Force India's "remarkable" reliability on its first day of running at Barcelona on Friday.
The Mercedes-powered VJM08 was the last of the 2015 cars to make its track debut, and will head to the Australian Grand Prix after just three days of running.
But Hulkenberg had at least a solid afternoon today, completing over 70 laps after just five rounds in the morning.
"From a running point of view it was very good," said Hulkenberg after the session. "Straight out of the box there was no issue.
"We did 77 laps pretty much only in an afternoon, which I think is quite remarkable, so the boys have done a good job there.
"Performance wise is very early to say. Obviously we are playing catch-up at the moment, doing the checks that everybody has done weeks ago. But as far as I can see it was a positive day.
"It's a start, it's a baseline, but we have a lot of work ahead of us."
Hulkenberg says it is too early to know how badly Force India will be hurt by the late start with the new car.
"I guess we'll only find out once we are in Melbourne. It's really hard to tell. It's not ideal. If we had more testing time with this car it would be better, but the situation is what it is and we will deal with it as best as we can.
"I think we have a good crew and usually we learn quite quickly. In this case we have learn quickly and then see where we can put ourselves into in Melbourne."