Ferrari made wholesale changes to its car after its drivers struggled throughout 2023 with its unpredictable behaviour and sensitivity to changing conditions.
That made it particularly hard for Leclerc and Sainz to keep up their race pace, often qualifying well before dropping far behind the Red Bulls.
But while Red Bull still has the dominant car, as evidenced by Max Verstappen's emphatic win in Bahrain, Ferrari believes it now has a much improved recipe.
"Generally it's just a bit chunkier with more chocolate on," senior performance manager Jock Clear said.
"It goes quicker everywhere under all conditions; more downforce, more power, lighter, because that's fundamental development. [In] all of those areas, the car is slightly improved.
"On drivability, we talked about this last year with the Ferrari and that's a big step we've made over the winter.
"Both drivers are much more comfortable with how consistent the car is and how much more predictable and drivable it is, so that when you're behind someone, when the wind conditions change, it's not scaring them."
Clear admitted that Ferrari "can't put a hand on our heart" claiming that its tyre management issues are entirely a topic of yesteryear, but felt that Ferrari had already made a step towards the end of last season.
"We think we understand the kind of things that allow you to improve your tyre degradation," he explained.
"It was a criticism levelled at us maybe two years ago and at the beginning of last year, but I think we demonstrated last year by the time we got to Vegas, you were seeing that Charles was able to manage the tyres just as well as Max.
"So, I think it's an area that we understand. And as such, we would be wholly expecting that we're continuing in the right direction with that."
Clears thinks both Ferrari and its rivals will have a better grasp of any strengths and weaknesses by the fourth race in Japan, as the challenging Suzuka is set to highlight them.
"The way that the calendar is this year, I think four races in we will have a pretty good idea because you've got Japan in there, which is a hell of a circuit to measure a car," he added. "So, at that kind of circuit, you're going to find out a lot."
