"The smallest guy here, with the smallest part into our engine, is a winner," non-executive chairman Niki Lauda told staff crowded into the 'pitstop' canteen for a champagne celebration at the Brixworth engine facility.
"I know how many hours you have to work, especially after Malaysia," added the Austrian, himself a triple world champion as a driver.
"We have to keep on going at the same pace and work...to make sure that none of our cars in the last races have any problems."
If Hamilton winced inside at the mention of a Malaysian race that blew a mighty hole in his championship chances nine days ago then he did not show it.
Instead, the Briton focussed on the fact that his 49 wins to date - with McLaren and Mercedes - had been powered by the German manufacturer's engines and looked forward to more success.
"Today is about all of you guys. I am so proud of everyone," said Hamilton, whose engine failed at Sepang just as he was heading for a victory that would have put him back in the championship lead.
Instead, after a subsequent troubled weekend in Japan, he trails Rosberg by 33 points with four races remaining and the knowledge that even four wins may not suffice.
"I'm just looking forward, there's still four races to go and I've got an incredible amount of support," the triple champion told Reuters when asked about the Suzuka weekend.
He joined staff in punching the air in triumph for a team photograph next to the cars, signed autographs and posed for selfies. Another celebration followed at the nearby Brackley team headquarters.
Mercedes team boss Toto Wolff, who travelled back from Japan with Hamilton on Lauda's plane, said the driver was in good shape.
"It's very difficult to fly back from a race that has been very difficult for you and where your team mate has scored a lot of points. But...he's a three times world champion, he's able to recover from that difficult moment," he said.
Asked whether winning the constructors' title meant the drivers were now unleashed for a full-on battle, Wolff told Reuters nothing had changed.
"We have always kept them racing, actually we have had no team orders and that is exactly the same way we want to continue - and hopefully not let them down with mechanical issues."
(Editing by Ed Osmond)
