Mercedes: 'On the limit' cooling compromised Hamilton in Oz

Mercedes have explained the cooling issues faced by Lewis Hamilton in Melbourne that sparked the Briton's "difficult position" radio message.

Hamilton spent the first part of the Australian Grand Prix running among the top four, but after his pit stop the seven-time world champion dropped to sixth and lost out to Mercedes teammate George Russell.

The pair eventually found themselves running together in third and fourth, having directly benefitted from the retirement of Red Bull's Max Verstappen.

While following Russell, Hamilton radioed in to tell his crew: "You guys put me in a really difficult position."

The message was initially interpreted as a criticism by Hamilton of his track position, a perception the Briton clarified after the race, as did Mercedes motorsport strategy director James Vowles in the team's Australian Grand Prix debrief on YouTube.

"That was all about engine cooling and keeping the power unit cool during the course of the race," Vowles said.

"We push everything to the limit, as you would imagine, and one of those is engine cooling, and you do that by closing up the bodywork or changing the louvre design at the back of the car.

"That decision is made on Saturday but obviously we are racing on Sunday, 24 hours later, and in this particular circumstance, the ambient was one or maybe two degrees warmer than we had expected.

"As a result of that, ourselves - and not just ourselves, you would have heard it from teams up and down the grid - were right on the limit of what the engine and the PU can take in terms of cooling requirements.

• Read also: Hamilton 'chasing aero guys' to solve W13 porpoising issue

"During the course of the race, when you are following a car, it meant that Lewis had to compromise what he was doing," added the British engineer.

"He had to move out of the dirty air of the car in front of him and make sure he got cool, clean air through the radiators to drop the PU temperatures down.

"But doing that makes racing the car in front incredibly difficult, and that's why his message came out."

Mercedes has yet to solve the porpoising issues impacting its W13 Silver Arrow and which are compromising the car's performance.

As a result, the Brackley is still clearly trailing its Ferrari and Red Bull rivals.

"In terms of where we were in Melbourne, we have to face the reality: we were a second down in qualifying relative to Ferrari and in the race, Leclerc was in a league of his own," Vowles said.

"Bahrain ended up being still to this point in our season our most competitive race, as an example, as a gap relative to the front.

"Every race though that we move forward, we have a plan of action of what we need to test, try and develop on that car and I am sure all of our competitors have the same thing.

"But the key is this: we have to start clawing back that gap to the front."

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