Mercedes is expecting this weekend's Mexican Grand Prix to be its most difficult race out of the remaining four in 2019.
Following the race in Mexico City, Formula 1 will travel to USA, Brazil and Yas Marina, with Mercedes already crowned as world champions after it picked up the constructors' title in Japan.
Since F1 returned to Mexico in 2015, Mercedes has won the event twice, with its last victory coming in 2016.
Red Bull and Max Verstappen has taken victory at the last two events at the Autodromo Hermanos Rodriquez - and Mercedes is expecting another tough fight this time around.
"There is no sense of entitlement in this team for future success, so we were quickly back to our usual race preparation routine after Japan," said team boss Toto Wolff.
"We know that the four remaining races are not going to be easy and we expect Mexico to be the most difficult one for us.
"The high altitude of the track brings some fairly unusual challenges as the low air density affects the downforce of the car, the cooling and the engine performance.
"It's a combination that doesn't particularly suit our car, but we will give it everything to try and limit the damage. We look forward to the fight and to the amazing Mexican crowd that shares our love for racing and turns the weekend into a brilliant celebration of motorsport."
With the constructors' championship wrapped up, only one of the two Mercedes drivers can win the drivers' title, with Lewis Hamilton the clear favourite as he holds a 64-point lead of Valtteri Bottas.
"When we embarked on this journey, no one would have dreamed we would ever be able to achieve this," Wolff said.
"We hoped that we would be able to win races, maybe even a championship and represent the Mercedes brand well - but to win six consecutive double championships and beat a record that seemed unbeatable is very satisfying.
"It's an achievement that is testament to the hard work, great determination and passion of every single member of our team.
"Everyone in Brixworth and Brackley has done a tremendous job and we all feel very grateful to call ourselves world champions for a sixth consecutive time."
Bahrain International Circuit - Winter testing