Grosjean was restricted to just 13 laps in the morning session after his Ferrari-powered VF-16 lost its front wing on track, bringing out the red flags, but returned in the afternoon to complete a further 18 laps.
With new parts due to arrive tomorrow to resolve the wing issue, the Frenchman says both the car and the team’s organisation have left him very encouraged.
“It went pretty well to be fair,” he reflected. “After an epic last few days to get everything together, the guys did an amazing job and the car felt good, which is always important to get a good first impression.
“There have been a few things but everyone is on it, we have good people on our side - we have a brand new team, a brand new car and livery and name, but there is a lot of experience behind it.
“The way we were able to go out, do laps without having big problems - no leaks, no electrical failures... there was the small issue with the front wing, but we understood the problem quickly and we will have it fixed for tomorrow.”
Asked about his gut feel after driving Haas’s first F1 car, Grosjean added: “There are always problems coming into a year, but generally I think we will be ready for Melbourne.
“Generally we are very happy with where we are - we are not far from being able to be midfield.”
Grosjean finished 10th fastest of Monday’s 11 runners in Spain, just over three seconds down on the pacesetting Ferrari of Sebastian Vettel.