Lewis Hamilton says he and Mercedes can't afford to make any mistakes with how they approach their tyre strategy this weekend at the German Grand Prix in Hockenheim.
Hamilton was second fastest in both first and second practice on Friday. He wants to make sure they are not pipped to victory again as they were last time out in Silverstone at the British Grand Prix.
"We've got through our programme today," he said, after a drama-free Friday. "We finished all the sessions and got all the information we needed from the tyres. The car was feeling good.
"But it is very close,"he admitted, after being pipped to the top spot in both sessions by Red Bull. Daniel Ricciardo was fastest in the morning, and Max Verstappen was 0.026s faster than Hamilton in the afternoon.
"There's lots of work to do tonight," he acknowledged. "We've been working on our starts, making sure to get a better understanding of the tyres and tyre temperatures and trying to be as perfect as we can in that area.
"Both Ferrari and Red Bull were very quick today and I think it will be very similar tomorrow and on Sunday.
"It's going to be a serious challenge and it's not an easy track to get right, so we will have to give it everything.
"It's quite a technical track even though it is a pretty short circuit," he added. "The weather is amazing: it's very hot, which makes it very demanding and physical in the car."
The heat meant that several drivers suffered from blistering when completing distance runs on the ultrasoft tyres. It could force teams to reconsider their plans for Sunday's race strategy.
"The hot conditions are definitely making life difficult for the tyres," reported Mercedes chief race engineer Andrew Shovlin.
"The ultrasoft is really on the limit. It's got good grip to start but needs to be driven ever so gently to keep it from blistering.
"The soft and medium are a bit easier to lean on which may mean that we see a range of strategies on Sunday, which should lead to an interesting race.
"We expect the weather to cool a bit going into tomorrow," he added. "[That] will make working conditions more pleasant and will help the tyres a little bit.
"It's always difficult to know quite where we stand on a Friday," he said. "We have seen good times from both Ferrari and Red Bull so we expect it to be tight tomorrow in qualifying
"But there are a few areas where we can find a bit of pace."
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