However, the tweaks - and particularly upgrades related to the rear suspension - ended up derailing their campaign.
"We didn't go and develop in the right direction, so clearly we missed something and not because something was on goal by default set wrong". So it's up to us to find a fix for it and make sure it doesn't happen again, but it's not so simple to find and fix it as it sounds.
"But it's not so simple to find and fix it as it sounds".
Hamilton switched to full Mercedes business however in time for his press conference - in white, branded shirt and cap - where he threatened to leave F1 if the calendar became too bloated.
"I have been three times now I have been in a position like that", said Vettel on his title defeat.
"So hopefully we can keep that up and keep competitive here and in Abu Dhabi and give [Mercedes] a very hard time".
Fresh from winning his fifth world title, Hamilton arrived for pre-race preparations at Interlagos in a tracksuit and denim jacket combination.
As a result, Ferrari must outscore Mercedes by at least 13 points in the Brazilian Grand Prix to remain mathematically eligible to win the constructor championship heading into the 21st and final race of the season.
"Right now, the focus is on making sure we secure this title in the next two races for the team".
"That's on my to-do list so we can collectively do that this weekend or next weekend".
But Hamilton has insisted there is no Mercedes plan in place to ensure Bottas gets his win back.
"I am someone that really loves racing, but the season is long, it takes a big commitment from all of us, and it is a long time away from our families".
"It would be great for him to finish on a strong note, feel better in the vehicle and finish off the year strong". All I can speak is for myself.
"I don't know if I would be doing Valtteri any favours in giving him a win", he added. "You all know what my goal will be for this weekend, so it's going to be up to me and I need to perform at my best level to fight for the win".
But the early signs are promising for them, after Max Verstappen, the victor last time out, topped the opening-practice timesheet on Friday - though less than a tenth of a second split the top three...