Stoffel Vandoorne got his first taste of the MCL33 on Tuesday, in the second day of pre-season testing at the Circuit de Barcelona-Catalunya.
His team mate Fernando Alonso had the honours on day 1, only to make an early excursion into the gravel with a broken wheel nut.
There was no such drama for Vandoorne, who said it had been a positive day for him - despite an issue with the car that limited his afternoon running to just five laps
"All in all it’s been a positive day with a lot of thing learned," the Belgian driver said after the session concluded.
"It was very nice to get back in the car after the winter," he said. "It felt like I hadn’t left the cockpit.
"The first impression is very positive, felt very comfortable, no surprises - some good learning done," he reported. The switch from Honda to Renault power units hadn't caused him any concerns.
“There are no big things to say really," he said. "Everything feels nice, drivability feels very good. Every setting we change are working as expected. So far there’s nothing much to tell."
However, the team did suffer a setback when some burn marks were spotted on the rear bodywork of the car shortly after midday.
"Unfortunately we had this small issue with the exhaust clip," Vandoorne acknowledged.
"[It] obviously detached the exhaust and blew a lot of hot air on some of the wiring looms.
"One of those wiring looms was the brake wire as well," he explained. "So the team took a precautionary check, which obviously meant things took a bit longer than expected."
Otherwise the only issue that Vandoorne experienced was the chilly conditions. The day started with air temperature at freezing, and concluded with sleet and snow showers.
"Mainly what held us back was the weather conditions," he confirmed. "Obviously [it was a] very cold and damp circuit. That took a while to get the running started for everyone."
Vandoorne went on to set the third fastest time of the day. His lap of 1:20.325s was completed on the new Pirelli hypersoft compound, despite the cold track surface.