Kevin Magnussen has admitted that he is struggling with preserving his rear tyres at this weekend's Malaysian Grand Prix.
Magnussen was 12th quickest during a second practice session in which the Dane battled oversteer in his McLaren MP4-29.
"I’ve never driven a car in these sorts of temperatures – so I learned a lot today," he said.
"As I say, the track temperatures are so hot here that the tyres are really suffering – but it’s the same for everyone, so we need to try and get on top of things before tomorrow’s sessions. I’m going to try and set the car up in order to protect the rears.
"There’s always something you can improve, and we’ve currently got a lot to think about and a lot of data to sift through tonight. For me, overheating the rears is my biggest problem – the tyres are behaving very differently from how they did in Australia – so that’ll be my focus."
Team-mate Jenson Button added that McLaren is suffering through the high speed corners, of which they are several at Sepang.
"We’re finding it tough out there today – especially in the heat," he said. "We’re not as strong as we’d like to be in high-speed corners – and, when you have downforce issues, they’re further amplified by the hot weather. So our long runs were tricky – in terms of both tyre degradation and outright pace. We’re now going through the data, but the upgrades we brought here seem to be giving us something – so that’s encouraging – but there’s a lot of work still to be done."
The Brit warned that McLaren is off the pace on long run simulations.
"I’m sure people are getting excited about individual lap-times, but they don’t count for too much around here because you can usually overtake," he said. "It’s the long runs that you need to analyse, and that’s where we’re finding it a bit more difficult."