Lando Norris was McLaren's fastest man this week at Barcelona's in-season test, running in both the team's old and new-spec cars.
The McLaren junior handled development work for Pirelli on day 1 before getting down to business in the upgraded MCL33 on Wednesday and clocking in with the third fastest lap overall.
Norris' 1m18.039s effort on soft tyres was faster than Stoffel Vandoorne's lap on the supersoft compound the day before, although the relative performance may have been achieved on a lighter fuel load.
Still, the 18-year-old and current leader of the F2 championship was delighted with his two days of work at the Circuit de Catalunya, which also marked his third run behind the wheel of a McLaren.
"Jumping from F2 is still a fairly large step, and it does take a bit of time to get used to it," Norris said.
"There are definitely things we need to improve and work on, but the car is still very good to drive. It does give me a lot of confidence to carry the throttle and I don't think I'm on the limit yet."
The McLaren junior offered a straightforward assessment of the differences between the MCL33 fielded at the start of the season and it updated counterpart which appeared in Spain last weekend.
"This test has been a very good opportunity for me to get up-to-date with this car and the new power unit.
"It’s good that I can show the team what I can do, but I see it more as an opportunity for me to keep learning and developing, and learn from both Stoffel and Fernando over race weekends, rather than proving that I can do a lap-time.”
"There are definitely some differences in the two specs - positive in many ways, but there are still some things with the old one that are also positive, so it's all about combining the two which will make the car even faster," he said.