Fernando Alonso was satisfied with his day's work at Barcelona on Thursday as he says Ferrari have gained a "good understanding" of the Pirelli tyres.
The double World Champion has been in action at the Spanish track for the past three days and spent his final day concentrating on tyres.
Amassing 97 laps and setting the day's fastest time, a 1:21.875, Alonso reckons Ferrari are getting a handle on the Italian rubber.
"Today we concentrated on a comparison of the compounds, starting with the Soft and moving on to the Hard," said the 31-year-old.
"The track was colder than yesterday, especially in the morning, which made it harder to adapt the car and find the right grip level.
"We tried various aerodynamic configurations and for the first time, we made some set-up changes to get a good understanding of tyre behaviour and degradation.
"With every change we made, the car reacted as I expected and it was useful to try out the different settings, especially to understand which direction we need to go in next week, when there will be a greater emphasis on performance."
And one of the "crucial" aspects in performance is the tyres.
"They are softer and quicker, but also less consistent and they degrade rapidly with every lap. We will have a lot of work to do to understand how best to balance the car, but that applies to all the teams."