Ferrari driver Sebastian Vettel has sampled Pirelli's 2017-sized tyres for the first time during a private test at Fiorano, run by the Italian company.
Pirelli has begun a period of intense tyre testing as it prepares its 2017 rubber, which will be 25% wider at both the front and rear of the car.
Vettel sampled the wider tyres in dry conditions before conducting wet weather running in a modified version of Ferrari's 2015 car, tweaked in order to simulate 2017 downforce levels.
All Formula 1 teams will have access to the same data package gathered during each test, ensuring that no squad gains an unfair advantage.
Esteban Gutierrez will conclude running at Fiorano on Tuesday, with Sebastien Buemi carrying out testing in a modified version of Red Bull's RB11 at Mugello on Wednesday and Thursday.