Having lost the Driver's Championship, Jonathan Legard asks if Sebastian Vettel and Ferrari will have a lot of work to do if they are to succeed in 2019. (1:31)

Lewis Hamilton may have secured his fifth drivers' crown in Mexico, but the championship that determines how a large chunk of prize money is distributed between the teams is still up for grabs. It's also the title that team members' bonuses are attached to -- for example, every full-time Mercedes employee in Brackley -- from engineers to catering staff -- are due to receive a minimum payment of £10,000 if the title is won.

"It's the constructors' championship that pays the mortgage of the colleagues and pays for the Christmas gifts," Mercedes boss Toto Wolff said in Mexico. "And that one is still on."

It's no coincidence that team bonuses are linked to the constructors' championship instead of the drivers' championship. A significant part of Formula One's revenue is divided among the teams based on their finishing position in the standings, and the higher you finish the more you earn.

Mercedes leads Ferrari by 55 points in the constructors' championship ahead of the final two rounds. Charles Coates/Getty Images

Mercedes currently leads Ferrari in the constructors' championship by 55 points with a maximum of 86 points still up for grabs over the remaining two races. With both cars contributing to constructors' points, the various permutations are too long to list, but if Mercedes get both cars on the podium in any order they will win the title in Sao Paulo regardless of Ferrari's result. Alternatively, if Ferrari gets a one-two, the title will definitely go down to Abu Dhabi.

Put another way, Ferrari must outscore Mercedes by 13 points or more to keep the title alive beyond Brazil (and then hope to outscore Mercedes by the rest of the current points difference in Abu Dhabi to win the title!) To put that target in perspective, Ferrari reduced the gap by 12 points at the U.S. Grand Prix and by 11 points in Mexico after Mercedes struggled for performance at both rounds. Extrapolating that trend over the two remaining races would not be enough for the Italian team to secure the title, but if Mercedes suffers retirements at either of the next two races -- as it did with both cars in Austria earlier this year -- the championship would be wide open. However, it should be noted that Ferrari has not scored a one-two victory all season while Mercedes has taken four.

Red Bull has guaranteed third place in the constructors', while Renault now appears to be the favourite to secure fourth place. Haas' failure to score points in the U.S. and Mexico have proved extremely costly for the American team, while Renault has scored 22 points in the same timeframe. The gap between the two now stands at 30 points, meaning Haas would need to break into the top six regularly with both cars to turn the situation around.

Haas and Renault have been battling over fourth in the constructors' championship all year. Charles Coates/Getty Images

Haas' fifth place is also looking safe, with McLaren, which scored its first points in four races in Mexico, 22 points behind. Force India was forced to sacrifice 59 points after it went into administration over the summer break so that it could re-enter the championship under new ownership at the Belgian Grand Prix. The team could still snatch sixth if it can outscore McLaren by 15 points over the next two races, but if the 59 points had not been revoked it would be just eight points shy of Renault going into the final two rounds.

Sauber has had a strong second half to the year and overtook Toro Rosso for eighth place at the Mexican Grand Prix. Challenging for seventh would require the Swiss team to outscore Force India by 11 points, which seems unlikely given the relative performance of the two teams at recent races, but would be possible if Force India fails to score as it did in Mexico.

Meanwhile, Toro Rosso will be keen to regain eighth from Sauber, with just three points dividing the two teams. However, it will require a step up in form -- especially on the reliability side after a spate of Honda engine changes have resulted in grid penalties at recent races.

The once-great Williams team looks destined for its worst championship finish in its 41-year history. It sits at the bottom of the standings on just seven points.