Carlos Sainz was left smiling when he felt the effects of Formula 1's new regulations as he put in the first laps at pace in his new STR12.
The Spaniard took to the Circuit de Catalunya-Barcelona on Monday morning as pre-season testing got underway.
It was the first time that the Spaniard experienced Formula 1's new tyres and downforce levels at speed, and it was an experience he thoroughly enjoyed.
"I end the day with a positive feeling after my first outing at the wheel of the STR12," he said.
"Everything felt good and I'd say we've made a big step forward compared to last year in terms of downforce and grip – I felt it straight away during the first laps of the morning and it put a smile on my face."
The day, though, was not without troubles as Sainz covered just 51 laps before Toro Rosso called an early end to proceedings.
"Of course it wasn't the smoothest of days," he added, "and we would've liked to complete more laps, but you know that this is always going to happen on the first day testing a brand new car.
"All in all, a decent first day and it's great that the season has finally kicked-off!"
— Toro Rosso (@ToroRossoSpy) February 27, 2017
Technical director James Key was satisfied with Toro Rosso's start especially as the Renault-powered STR12 behaved as expected.
"It's good to finally get started after such a long winter, completing 51 laps," he said. "Although we had to stop a little bit earlier with a bit of a niggle on the front of the car, we will get this sorted for tomorrow.
"The main priorities today were to get miles on the car and to do the basics right, so we did some aero work in the morning and after that we went through a long list of basic checks on our new car, considering there are so many things to learn.
"It was really all about laps and fundamentals today, and it will be the same tomorrow with Daniil.
"The good news is that, a part from the usual first-day glitches, nothing has caught us out and everything behaves in the way we think it should.
"The driver feedback has been close to expectation and generally quite positive so I think that, for a first day of testing and although we would've liked to do more laps, we can't complain at all. We didn't do any performance running – that will come later on."
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