Toto Wolff says that a power unit failure for Lewis Hamilton during the Brazilian Grand Prix was "imminent". The Briton won the race at Interlagos after Max Verstappen got tangled up with a backmarker during the Grand Prix at Interlagos.
Hamilton came over the radio to report that something was fishy with the engine while he was out on the track. Mercedes boss Wolff revealed that he received reports during the race from engineers that Hamilton's engine was about to give way, making for an anxious final stretch.
The Austrian said: "We have the engine guys here at the track and then we have them back at base, and what I could hear, because I have about ten radio channels open on one of the ten channels, the meeting channel, was 'Lewis Hamilton power unit failure imminent, it's going to fail within the next lap'.
"I put the volume up and I was like 'Excuse me, what?' And they said 'Yeah we've got a massive problem on the power unit, it's going to fail next lap'. It didn't fail next lap and I said 'When you guys have a minute, tell me what's happening". So I let them work.
"And they said 'Well our exhaust is just about to fail and we're overshooting all the temperature limits'. So I said 'What's the fix?' And they started to fix it by turning the whole thing down. The temperatures went down to below 1000C, to 980C, but it's still too high, and then he recovered another lap and that was truly horrible."
Hamilton had a gap of over five seconds to Verstappen after the Dutchman's collision with Esteban Ocon, but by the end of the race, the gap read just under one and a half seconds. Hamilton says that he was doing all he could inside the cockpit to ensure his engine stayed intact.
"There was a lot of great work done by the engineers here and back in the UK who were working on what they could turn down and tweak," he said. "So I was getting a lot of balls thrown at me while I was driving and trying to do all the other stuff, like switch changes, 'can you do a default setting?' and juggling that and they kept on throwing it at me.
"I was really grateful that the engine finished and for the last 10 laps I was really just shouting in the car 'come on baby, you can do it. Let's keep it together...' and willing on the car. You could never imagine how crazy that feeling is in the car when your heart rate is at, mine must have been above 190, those last 10 laps I was at flat-chat trying to hold on to a car, which was already struggling. I just felt so elated and so grateful."
Bahrain International Circuit - Winter testing