Toro Rosso had no 'headaches' in F1 testing this year - Sainz

At the end of winter testing, Toro Rosso sat second in terms of total mileage at Barcelona with 1049 laps to Mercedes' 1294.

While the team managed decent mileage in 2015 as well, it still encountered problems, and poor reliability cost it points on several occasions during the season.

"There are not so many headaches as we were having at this stage last year," said Sainz.

"We are doing laps, laps, laps, and nothing is breaking.

"We still have some small issues, I'm not going to lie, but the car is on track and this is what is giving us the best baseline."

Sainz said Toro Rosso's focus on reliability and curing its 2015 woes with the medium-compound tyre mean the team does not know where it stands relative to its rivals.

"We haven't really seen what we are capable of doing," he said.

"We have spent a lot of time on the medium, that was our weakest tyre last year, and we are really pushing that tyre to see what we were missing and how to improve it.

"We all try to answer these questions by looking at laptimes and fuel loads, but we need to wait until Melbourne.

"To be the second best team in laps behind Mercedes shows that this team can do really great things."