Sebastian Vettel topped another day of winter testing with Pirelli's new ultra-soft compound on a busy day which saw eight of the 11 drivers surpass 100 laps.
Vettel was quickest on the opening day at the Circuit de Catalunya and finished Tuesday 0.715s ahead of Daniel Ricciardo after bolting on the purple-striped ultra-soft tyre, which is new for 2016, for the first time. The tyre is unlikely to be used anywhere other than street circuits this season but Vettel and Red Bull, who put the compound on Ricciardo, were the first to roll them out. The only blemish for Vettel was a stoppage five minutes from the end of the session when he pulled up at Turn 3, prematurely ending the day's session.
Ricciardo finished second after his own ultra-soft lap and with 112 laps to his name in the Red Bull to mark another encouraging day. Sergio Perez finished third with a lap time of 1:23.650 set on the super-soft tyre and ticked off 101 laps in the Force India.
Nico Rosberg finished fourth on a day which saw Mercedes stick exclusively to the medium tyre. The team completed the all 12 days of winter testing last year without using the softest compound and showed no sign of attempting a quick lap throughout the session, with the world champions clearly focused on longer runs. The Mercedes had completed a race distance before lunch before Rosberg exceeded Hamilton's Monday tally, ending on 172 -- over 800km -- by the time the chequered flag fell. The fact Mercedes was even executing live pit stop practice suggests the world champions have made a lot of progress in working through its testing programme.
Sauber's Marcus Ericsson was next, completing 108 laps in the 2015-spec Sauber. Behind him was another Ferrari-powered car in the form of Haas' Esteban Gutierrez, who finished the day with 79 laps to his name. Surpassing a race distance on its second day will have been for Haas after arriving with a reinforced front wing following Romain Grosjean's failure on Monday.
Valtteri Bottas had a solid but unspectacular day for Williams, finishing with 134 laps overall ahead of handing the car over to Felipe Massa on Wednesday. Pascal Wehrlein ended the day eighth with 71 laps completed.
Fernando Alonso finished ninth in the McLaren MP4-30 but completed an impressive 119 laps. Honda managed just 380 in 12 days of testing last year so it will have been more valuable mileage for the Japanese manufacturer on a day its reshuffled F1 team was in the news. It is unlikely McLaren is chasing lap times at this stage with mileage and reliability the focus and the team will be encouraged by the first two days of testing.
There were more problems for Jolyon Palmer and Renault after the British driver stopped in the afternoon session with 47 laps to his name with what the team confirmed was a power unit issue. The stoppage came after his "challenging" opening day with the car and means he finishes his first two days in the car -- 50% of his driving time before Melbourne -- with just 79 laps completed.
The other red flag of the day was caused by Max Verstappen's stoppage in the hour before lunch after gearbox trouble. The plain blue Toro Rosso, powered by Ferrari's 2015 engine, stopped at Turn 13, but eventually returned to the track and completed 113 laps.
Times at close:
1. Sebastian Vettel - Ferrari - 1:22.810 - 126 laps
2. Daniel Ricciardo - Red Bull - 1:23.525 - 112 laps
3. Sergio Perez - Force India - 1:23.650 - 101 laps
4. Nico Rosberg - Mercedes - 1:24.867 - 172 laps
5. Marcus Ericsson - Sauber - 1:25.237 - 108 laps
6. Esteban Gutierrez - Haas - 1:25.524 - 79 laps
7. Valtteri Bottas - Williams - 1:25.648 - 134 laps
8. Pascal Wehrlein - Manor - 1:25.925 - 71 laps
9. Fernando Alonso - McLaren - 1:26.082 - 119 laps
10. Jolyon Palmer - Renault - 1:26.189 - 42 laps
11. Max Verstappen - Toro Rosso - 1:26.539 - 121 laps