Singapore Grand Prix: Mercedes face 'difficult task' stopping Sebastian Vettel
Mercedes say they face a difficult task stopping Ferrari's Sebastian Vettel retaking the championship lead in Singapore on Sunday.
Mercedes driver Lewis Hamilton moved ahead of the German for the first time this season with victory in Italy.
The Briton leads Vettel by three points as they head to the slow and twisty Marina Bay track this weekend.
Team boss Toto Wolff said: "It is a circuit that we have found difficult to master"
He added: "We head to Asia with the expectation that we have a big challenge ahead of us."
Mercedes were beaten by Ferrari in Singapore in 2015, when they had their least competitive weekend of an otherwise dominant year, and were run closer there last season by Red Bull and Ferrari than at virtually any other track.
The Ferrari has proved much more competitive than the Mercedes on slow tracks in hot climates - they took one-twos in both Monaco and Hungary.
"As we have pushed to become better and stronger in every area, we have put the finger in the wound in order to understand the root causes of both our good performances and the bad ones," Wolff said
"In 2015, Singapore provided us with one of the most painful experiences in recent seasons, so we rolled up the sleeves, learned from it and managed to bounce back with a great win last year.
"So far this year, we have seen the pendulum swing according to circuit type.
"On the surface, Singapore is the kind of circuit that should favour both Ferrari and Red Bull.
"Both have shown strong performance on low-speed circuits demanding maximum downforce, and we have found life more difficult at those places in 2017.
"Sometimes, characteristics like this are simply in the DNA of a car. Nevertheless we learned a lot from our struggles in Monaco, raised our level of performance significantly in Hungary and we have made good progress in understanding what we need to do in order to get the most from the chassis."
Hamilton said after his back-to-back wins in Belgium and Italy: "The learning from these two weeks should collectively put us in a better position for Singapore but I think still Ferrari are going to be quick there. They are rapid through the medium and low-speed sections of circuits.
"We will do all the diligence possible to arrive best prepared. We have learned a lot from the past.
"Ferrari are often better in hot places but I think we will be able to give them a good race. The car is constantly improving and if we went back to Hungary, for example, maybe we would be in a better position having already been there.
"I am going [to Singapore] with a positive approach expecting to fight for the win, but if we can't we take it at face value and damage limitation."