Pierre Gasly says Friday evening's cooler conditions in Bahrain weighed on the performance of AlphaTauri's AT03, with the Frenchman unable to uphold the leading pace he had shown in FP1.
Gasly had clocked in with the fastest lap at the end of the afternoon session, comfortably outpacing both Ferrari drivers in the session.
But as the sun went down at Sakhir and temperatures dropped for FP2, reflecting the conditions that will prevail in qualifying, Gasly and AlphaTauri teammate Yuki Tsunoda lost ground and could do no better than P13 and P14, with both drivers struggling, among other things, to put heat in their tyres.
"We've had two very different sessions," commented Gasly. "We topped the timings in FP1 and then in the second session we were P13, so two very contrasting outcomes.
"I think, purely for us, the hotter track conditions helped, the car really seemed to click, but [in the evening] we struggled massively in the cold.
"We need to look through everything and understand what happened, especially as qualifying and the race are both at night here in Bahrain.
"Obviously, it’s very different conditions, the tyres are behaving very differently.
"I think our long-run pace was slightly better than the shorter runs, but still we've got a lot of work to do to fully understand our performance in these conditions."
AlphaTauri chief race engineer Jonathan Eddolls acknowledged the AT03's sensitivity to the cooler conditions but insisted that there was nothing "fundamentally wrong" with the Italian outfit's car.
"We hit the ground running in FP1 but then had mixed fortunes going into FP2, where we were not able to follow the changing track conditions and both cars suffered with a lack of grip and difficult balance," he said.
"Not only did we struggle more, it also appeared other teams made quite a step up in performance between FP1 and FP2, which emphasised the gap.
"Fundamentally there isn’t anything wrong with the car, as we showed in FP1, so we have a lot of work ahead of us tonight to ensure we understand the FP2 performance and make the relevant changes to the car for tomorrow.
"This is particularly important for Qualifying, as the track temperature will be similar to this evening."
Keep up to date with all the F1 news via Facebook and Twitter
