They are still on a high after successfully defending their titles in 2015, but Mercedes are bracing themselves for what will "undoubtedly" be their "biggest test yet" in 2016.
Mercedes have swept all before them since the introduction of the V6 turbocharged power units in 2014 with the team claiming 31 victories in 37 grands prix and taking pole position in 35 of those races.
Naturally it meant back-to-back doubles with Lewis Hamilton winning the 2014 and 2015 Drivers' Championship and Merc securing consecutive Constructors' titles.
Ferrari, though, have made up some ground and Merc non-executive chairman Niki Lauda believes the Scuderia's power unit is now at the same level as that of Mercedes.
Although they remain the team to beat, Mercedes motorsport boss Toto Wolff feels they will have a big battle on their hands come 2016.
"We can all be extremely proud of what we have achieved in 2015," he said. "To raise the bar from 2014 was always going to be a huge challenge – but everybody at Brackley, Brixworth and Stuttgart has taken on that challenge exceptionally well.
"While we celebrate a job well done this time around, however, the next challenge will be upon us before we know it. 2016 will undoubtedly provide our biggest test yet as a group."