Taking his work from the simulator to the track, Esteban Gutierrez says he has a "very good feeling" about Ferrari's new aero package.
The Mexican racer was in action on Day Two of the post-Spanish Grand Prix test.
It was his first run in the SF15-T as Gutierrez, who had up until Wednesday only conducted simulator work, got a feel for the car in track conditions.
His programme for the day consisted of an in-depth analysis of the new aero package that Ferrari, who bookmakers Paddy Power are backing ahead of the Monaco GP, introduced at the Spanish GP.
"Our work was aimed at the upcoming races, looking at various aspects, such as driveability, aerodynamics and set-up. We managed to complete a lot of laps and it was definitely a very productive day, even though it was interrupted by a red flag," said the former Sauber driver.
"However, we managed to make up for lost time and complete our planned programme. We were looking to validate the new aerodynamic package and we managed that.
"It was a case of understanding how to improve the car's set-up to better suit the new solutions we ran in the last race and that's what we did. It was very exciting to drive the SF15-T for the first time and I got a very good feeling from it."
Gutierrez, whose team-mates Vettel and Raikkonen are firm favourites for the Monaco podium having featured in the top three in all the five proceeding races, finished the day seventh quickest, 1.850s off the pace, and with 119 laps.
He added: "It will be very interesting to transfer this data to our work in the simulator, once we are back in Maranello."