Designed under James Allison and a team that now included Ashley Way, Emiliano Giangiulio, and Eric Blandin alongside returning figures Aldo Costa and Loïc Serra, the W10 represented Mercedes' first response to the revised 2019 aerodynamic regulations. The team ran two distinct aerodynamic packages during pre-season testing — informally dubbed the A-spec and B-spec W10, differing principally in front wing philosophy — before selecting the outboard configuration for racing. The chosen package also featured a substantially revised nose, bargeboards, floor, and engine cover.
The car was noted from early in the season for its strength in slow- and medium-speed corners, a shift in characteristic from the W09. It completed 5,535 kilometres across eight days of pre-season testing. Reserve driver Esteban Ocon backed up the regular pair; George Russell and Nikita Mazepin also drove the W10 in in-season tests.
A weakness emerged in Austria, where tight cooling packaging caused overheating under high-altitude conditions. A rear-end upgrade in Germany addressed cooling efficiency. A further upgrade package in Japan revised front wing, sidepod deflectors, and floor, aimed at narrowing Ferrari's straight-line advantage on the remaining circuits.
The new-for-2019 Mercedes-AMG F1 M10 power unit was considered the most fuel-efficient in the field but was conceded to be less powerful in outright qualifying mode than Ferrari's 064 unit. Three engine specifications were deployed through the season, with the Phase 3 unit experiencing significant failures at the Belgian and Italian Grands Prix.
The opening four races set the tone for the year. Bottas won in Australia with a lead of over twenty seconds. Hamilton won in China, producing his third career grand slam, and Bottas won in Azerbaijan in what became a record four consecutive 1-2 finishes at the start of a season, surpassing Williams' record from 1992. Hamilton won in Spain and Monaco — the latter in what he described as "probably the hardest race" he had experienced, managing heavily degraded tyres to hold off Max Verstappen in the closing laps.
Ferrari mounted a serious challenge after the summer break. Charles Leclerc won in Belgium and Italy on consecutive weekends with a car that was clearly superior on low-drag circuits. Ferrari also dominated Singapore qualifying and outpaced Mercedes in Russia before team order conflicts and a power unit failure for Vettel handed the race to Bottas. Mercedes clinched the Constructors' Championship in Japan with four rounds remaining — the sixth record-equalling title.
Hamilton secured the Drivers' Championship at the United States Grand Prix after Bottas won from pole, with Ferrari unable to match Mercedes' race pace. The season closed with Hamilton dominating in Abu Dhabi with a grand slam — pole, fastest lap, every lap led, and victory.
At Monaco, Mercedes paid tribute to Niki Lauda, who had died on 20 May 2019. The halo device was coloured red bearing the text "Niki we miss you"; the nose carried Lauda's signature alongside "Danke Niki" and a red three-pointed star. At the 1,000th Formula One Grand Prix in China, commemorative logos appeared on the bargeboards and nose cone. At the German Grand Prix, the car raced in a half-silver, half-white retro-inspired livery marking 125 years of Mercedes involvement in motorsport.
The W10 made Hamilton the most successful driver in Formula One history by multiple measures. His sixth title tied him with Schumacher's all-time record, which he would break in 2020. Hamilton also became the first driver to win the Canadian Grand Prix seven times, surpassing Schumacher's record at that circuit. The car demonstrated that Mercedes could match or beat Ferrari even in a season where their power unit was openly conceded to be less powerful in qualifying trim — a testament to the team's structural depth in chassis design, strategy, and tyre management. A modified W10 was later used during Pirelli's 2022 tyre compound testing following the 2021 Abu Dhabi Grand Prix.