Sainz was unable to post a flying lap in Q1, and was thus classified 20th. Engine supplier Renault traced the source of the problem after the session, but no decision has been taken on whether the Spaniard will take any new components ahead of Sunday’s race.
He has a high-mileage “Friday” engine that was used yesterday, but there would be no extra penalty if he takes a new V6, as he is already at the back.
The team also had the option to make changes to the specification of the car – such as taking out drag to make it easier to overtake – which would lead to a pitlane start.
“It’s still open at the moment,” said McLaren team boss Andreas Seidl. “We still need to figure out what we want to do, what were the consequences. And we also have a first analysis now, which means that the wiring system of the of the ignition failed and that was causing a power loss Carlos felt and nothing we could fix.”
Sainz admitted that managing his tyres would be the biggest issue as he tries to make progress through the field.
“It’s maximum attack I guess,” he said. “Obviously, maximum attack doesn’t always work with Pirelli tyres. So it will be a compromise between managing the tyres and going maximum attack. So it’s probably a very difficult thing to do, but somehow you must always find a way.”
Sainz’s teammate Lando Norris could manage only 11th place – which is 10th on the grid after Charles Leclerc’s grid penalty – after a clean qualifying session, indicating that there’s been a drop-off in form at Interlagos compared to recent races.
“I guess we’ve seen some trends this year in some tracks that there are certain types of corners where we are not very strong,” said Sainz. “And probably this track has many of those type of corners. And that’s why your relative performance drops depending on track to track, and also it doesn’t mean that more we cannot make it to the points.
“It just means that it’s going to be probably a lot tougher, or tougher than Austria, for example, where it was a good one. But it doesn’t mean that we cannot do it. It just means that we need to do better.”
Norris believed that he had got as much out of the car as he could.
“It was just hard to improve a lot with the balance,” he said. “So I was pretty happy. We made some good progress from yesterday into today. I was much happier with the car but it wasn’t a car where I was able to extract more and more out of the new tyres.
“So it was more we were limited with what we had or I felt like I was limited and therefore I can make big improvements. But I was happy with the balance.”
Norris will have the advantage of being the first driver on the grid with a free choice of tyres.
“Whatever tyres I’ll be starting on, they will be new tyres,” he said.” So it will be an advantage to at least a couple guys ahead of me. It’s P10 as well because of Leclerc’s grid penalty.
“That’s the one, or the biggest positive out of all of this, whether we choose hard, medium or soft, we don’t know yet but the opening couple laps and off the line should be an advantage on what we have.”