Sainz and team-mate Max Verstappen qualified fifth and sixth respectively in the Spanish Grand Prix, but fell away in the opening laps of the race. Having been working on tyre management on high fuel during this week’s in-season test, Sainz said the basis of the car is strong enough that it won’t be updated for another three races.
Asked if there had been any new parts tested on Wednesday, Sainz replied: “No, no parts, the car is the same as it was on Friday with the new parts for the race.
“We will remain like this until Austria, we have to optimise our package and improve what we have. It is a very nice package and we will see what we can do in the next races.”
And Sainz says the focus was on learning about the car rather than trying to prepare for upcoming races.
“We didn’t look too much into Monaco, it is a completely different track to here. We focused on our weaknesses of the weekend. We had a good opportunity to learn and that is what we did.”
However, Toro Rosso’s running was not without reliability issues after Sainz stopped at the entry to the pit lane.
“We had an ERS failure, which is not ideal because you want to complete as many laps as possible. This is a great opportunity, only one in season test for me, we lost a bit of mileage there. The parts were repaired, we put new ones back on and it was fine.”
Click here for Wednesday's gallery from testing at the Circuit de Catalunya