|Tire width comparison|
Mercedes and Ferrari continued Pirelli's 2017 tire development program with slick-tire tests at Paul Ricard and the Circuit de Barcelona-Catalunya on Tuesday.
For the 2017 season, Pirelli's tires will be overhauled, with the fronts 60mm wider, extending from 245 to 305mm, and the rears 80mm bigger, going from 325 to 405mm.
Sebastian Vettel and Esteban Gutierrez first sampled the 2017-size tires at Ferrari's Fiorano test track early last month, before Red Bull fielded Sebastien Buemi at Mugello.
On Tuesday, Mercedes started a three-day test in southern France with Pascal Wehrlein, while Ferrari kicked off a two-day session in northern Spain with Kimi Raikkonen.
Mercedes will return to Paul Ricard for a wet-tire test later this month.