Carlos Sainz Jr says he is proud of of how he matured as a driver in his sophomore Formula 1 season in 2016.
Sainz Jr raced in the shadows of teammate Max Verstappen last year, unable to show his true potential due to a slew of reliability issues.
However, the Spaniard was able to rise to the occasion this year after Toro Rosso got on top of its technical problems and Verstappen moved to Red Bull.
Reflecting on the season gone by, the 22-year-old says he was more than pleased with his personal performances.
"I think I have to be very, very satisfied, it's not easy in Formula 1 to get a full year performing well," he said.
"It's been a good run of a lot of races performing at a very high level with a lot of points since Spain, I think with few mistakes, so I can be very proud.
"I feel like a completely different driver to 2015, both in terms of results and in terms of feeling.
"The feeling I have nowadays in Formula 1 is very different to the one I had at the end of 2015, and I'm proud of that, as it's exactly what I wanted.
"In 2015 I was probably a very frustrated driver with a lot of reliability problems, not being able to show my full potential, and I knew that 2016 was time to show it."
Toro Rosso’s fortunes nosedived in the second half of the season as the weaknesses of the year-old Ferrari power unit became evident.
Sainz Jr, who still managed a sixth-place result during the latter part of the year, believes the performance of STR11 started to fade from July’s German Grand Prix.
"Hockenheim was the turnaround point, we were coming from Baku, Canada, Austria, all power limited tracks and we were still getting into the points," he added.
"Suddenly we arrived to Hockenheim, and I don't know what people did there, we qualified with the same set-up, same rear wing, but nothing changed.
"We suddenly fell from P8 in every race to P14, since that point, and with Monza, Spa and Japan coming next, I realised it was going to be a tough end to the season."
Toro Rosso will revert to Renault power next year, having signed a deal with the French manufacturer for latest specification of their power units.
Sainz Jr will remain a part of Toro Rosso's driver line-up for a third successive season, with Daniil Kvyat filling in the other seat.
by Rachit Thukral