Cape Town - Mercedes boss Toto Wolff has said there is no complacency creeping in at the Silver Arrows despite good fortune and recent wins putting them on the brink of both World Championships.
Wolff has labelled the Mercedes W08 as 'capricious' and a 'diva' throughout the 2017 season but after the races in Singapore, Malaysia and Japan, the team principal believes important lessons have been learned.
"We returned from those races with a lot more understanding of our car and of the reasons for the performance swings we have experienced this season," said the Mercedes boss.
"Some of that understanding is already being applied to the final races, some of it will flow into next year's project.
"But the bitter taste of our defeat in Malaysia once again confirmed that the tough days are the ones when you learn most - and when you lay the foundations for future success."
"We approach every race with a healthy dose of scepticism rather than wishful thinking, and our focus must be on making sure we score every point within our reach this weekend in Austin.
Wolff also said that the team are well aware they have benefitted from good fortune in recent races given Ferrari's frequent DNFs and are not letting the subsequent results paper over the cracks.
"Since we began the final flyaway leg of the season, we have seen a strong points swing in our favour in both championships.
"Good fortune has played its part, of course - and we have put ourselves in the right position to make the most of the opportunities that have come our way.
"But nobody within the team is allowing those good results to disguise the challenges we have faced."
Wolff concluded by praising both drivers for their recent efforts.
"Lewis has driven brilliantly this year - and since the summer break in particular, he has been on another level," said Wolff.
"It has been impressive to watch him extracting everything from the car and working with the team to solve problems and improve even further.
"Valtteri has had a tougher time in recent races - but he demonstrated his work ethic and character to deliver a strong weekend in Suzuka, and he will be aiming to build on this performance in the final four rounds."