The Italian said that, thus far, the car has performed as it was expected to and stressed that adding more overall grip remains the priority as the team embarks on a busy development programme.
McLaren has enjoyed an encouraging two days of testing in Bahrain so far, although it lost some valuable track time with a fuel tank issue on Thursday, which interrupted a race run.
“I think some of the weaknesses have been improved,” he said. “For instance, we are happier with the grip at the rear axle, which was one of the aspects that we wanted to work on. Overall there is more grip in the car.
“There are some aspects that we still have some work to improve, save the fact that the major performance opportunity remains overall grip.
“It's not like you need to correct features, you just have to put more grip on the car, which mainly comes from aerodynamic performance.
“But we have some more margin to improve, also from a mechanical point of view. And also in terms of interaction with the tyres. So in all these three aspects we plan to bring developments over the course of the season.”
Stella said that it was “good news” that the car has performed as predicted so far, especially given that it contains some novelties relative to last year’s MCL60.
“I would say that starting from a performance point of view, the car delivers what we expected,” he said. “So no big surprises, which in itself is some good news, because there's some elements of innovation in the car.
“I think the car is a good foundation for development, and is a step forward compared to last year's car.
“But, overall, I can see that many cars have made the step forward, which is normal. Everyone finds performance in every week of development.
“There's one car that seemed to have found a big step. Unfortunately, the car that was already the quickest last year.
“I would say the [chasing] group was already quite compact last year, and to me it looks like even more compact this year.”
Stella has previously made it clear that some innovations didn’t make it to the launch spec of the car that is running this week, but he stressed that, when they do reach the track, they won’t be of the scale that Red Bull has brought with the RB20.
“There are some areas of the car in this launch specification that have significantly evolved compared to last year,” he said. “Some of them are very noticeable. There are some other areas that have only incrementally improved.
“But we see in the background in development that there's actually quite a lot of potential, which we didn't exploit in time to make it for the launch car.
“We are confident in our development. We are confident in the concepts that we have in the car, but if anything, it's a matter of how far you are in the journey.
“And clearly they have been ahead in this journey. And they sort of keep this margin in terms of where they are positioned in their development journey.”
