Ferrari driver Sebastian Vettel threw down the championship gauntlet to Lewis Hamilton after completing a practice double for the Bahrain Grand Prix on Friday. The problem on Vettel's vehicle appears to be completely unrelated and he suspects it was down to a software glitch. Vettel won the season-opening Australian GP and Hamilton, who has secured both pole positions, won in China last weekend.
Ferrari appeared to be in more trouble in FP2 when Vettel's auto shut down in the same area of the track where Raikkonen stopped in the first session. The other side of the garage looks quite competitive and now we need to review which configuration was better from the two cars and then apply that for tomorrow.
By then, the leading drivers had all completed their qualifying simulations, with Mercedes' Valtteri Bottas slotting into second place by 0.041 seconds shortly after Vettel went top.
"These drivers are just so risky", the Briton said over the team radio, with both drivers later summoned to see the stewards.
Ricciardo was third in the evening session after being second fastest in the morning, with Ferrari's Kimi Raikkonen fourth after his afternoon session went up in smoke, the Finn abandoning his smoking auto and trudging off in the desert heat.
The solitary walk through the arid landscape in overalls and helmet, before being collected by a scooter, was an arresting sight - and also typical of a driver with "Iceman" tattooed on his left arm. He did 1:31.310 in the cooler evening conditions, with Raikkonen fourth after an engine change.
Button recently had a couple of days driving the 2017 auto in the simulator during a visit to the United Kingdom from his Los Angeles house, and Boullier added: "He is very talented".
The long runs looked like they had a bit more pace so that was probably a bit more representative.
Although Hamilton was just a quarter of a second off Vettel's best time, a number of his best laps were ruined by heavy traffic. But I'm used to being in a Finnish sauna, so it's no problem! With FP2 starting at 18:00 - the same time as qualifying and the race - conditions under the floodlights help deliver a more realistic pecking order than running in the heat of the day, and the signs suggest a close fight in qualifying on Saturday.
"I think they will be very, very quick in the next race but there's a lot of straights there as well and we've obviously got, I think, still the strongest power unit on the grid", commented Hamilton.
The "T-wing", fixed on the engine cover of the Finn's auto, broke free during the second session and was collected by Verstappen's Red Bull, damaging the car's floor.
Ricciardo's Red Bull teammate Max Verstappen was third and eighth fastest.
The Belgian rookie stopped at turn 10 in the opening practice session following another Honda engine problem which resulted in a delay to the start of his running later in the day.