World champion Jenson Button says he is now feeling perfectly comfortable with the McLaren car, after completing his two days of testing at Jerez.
The Briton admitted after the first test in Valencia that he was unable to fully focus on set-up work as he did not feel 100 per cent right inside the car.
But, after two days of work at Jerez, Button says is now fully integrated with the car and feels ready to begin pushing with it.
"My day was good. We did a lot of work yesterday with making sure I'm 100 per cent in the car and that my new home was comfortable. I feel great in the cockpit now," Button told reporters at the end of the day.
"Yesterday was a good day, we did a lot of set-up work in the wet and trying to get to grips with the two different tyres.
"For me today was a better day, because we could go out in the dry and it's the first time I've felt good in the car, good enough within the car to actually do set-up work and find a balance with the car and also work with different components. Today was a positive day.
"There is still a lot of work to do with the car. The basic car itself is a good baseline, I think. Jumping in the car today this morning I was immediately happy with the car, the basic car.
"But I also know there is still a long way to go before we have a car that's capable of winning races, but that's the same for everyone. This is testing."
He added: "A Formula 1 car is a Formula 1 car. There are different ways of getting the best car, but the feeling I have in the car is not that dissimilar to what I'm used to driving. It's not a completely different style of design.
"I feel like at home in this car. I don't drive the car and I feel I'm not a part of this. I feel I can feel everything that's happening with the car, and that's so important when you jump into a new car."
The McLaren driver, who managed 83 laps today, also downplayed the significance of having managed less laps than some of his rivals.
"I would like to do the next two days, definitely," said Button, who will be replaced by team-mate Lewis Hamilton from tomorrow. "But it's not about just going out and putting on as many laps as possible. We know our car is reliable and that's always important.
"When you are testing different things you don't necessarily need big mileage. We are doing back-to-back and set-up work and at the moment for me that's more important that putting big distances on the tyres.
Button caused the final red flag of the day when he stopped his car at Turn 6, but he said the problem was nothing too serious.
"Nothing severe. I had a warning light so I stopped the car. But there's no damage or anything."