The W06 was developed under Paddy Lowe, Aldo Costa, Geoff Willis, and their Brackley-based team as a refined rather than redesigned car. Hamilton noted during pre-season testing that "it is difficult to pick up any differences" between the two machines. Regulated changes to nose and front wing geometry were adopted, along with revised upper suspension geometry. In-season developments included square-shaped arches around the front wing endplates introduced in China, narrower sidepods with a lower air duct in Spain, a larger monkey seat for Monaco, an enlarged radiator to protect the power unit in Canada, and a curved rear wing for Belgium and Italy that reduced drag without sacrificing downforce.
The car completed 1,340 laps — 6,121 kilometres — across twelve days of pre-season testing at Jerez and Barcelona. Pascal Wehrlein, the 2015 DTM champion, drove the W06 during in-season testing.
The W06 started the season as strongly as its predecessor. Hamilton won the first race in Australia in a 1-2 finish, with Ferrari's Sebastian Vettel more than half a minute behind in third. The team had secured all but one race win through the season's midpoint. Rosberg won Monaco after Hamilton was caught out by a virtual safety car miscommunication at the pit wall, emerging behind both Rosberg and Vettel. Hamilton responded with victories in Canada and Britain, and won in Italy with a grand slam — pole position, every lap led, fastest lap, and race win.
One of the low points came in Hungary, where Hamilton received a drive-through penalty and Rosberg suffered a late puncture from contact with Daniel Ricciardo, ending Mercedes' streak of nine consecutive double podiums and twenty-eight consecutive races with at least one car on the podium.
Rosberg clinched Mercedes' second consecutive Constructors' Championship at the Russian Grand Prix — the fifteenth round. Hamilton took his third Drivers' Championship at the United States Grand Prix, the sixteenth round, with his tenth win of the season. He became World Champion with one race to spare.
The car's final record: sixteen wins (ten for Hamilton, six for Rosberg), eighteen pole positions, thirteen fastest laps, and twelve 1-2 finishes. The last figure broke Mercedes' own record of eleven set the previous year, and stood as the most 1-2 finishes by any constructor in a single season. The team's 703 points narrowly exceeded their own previous record of 701 from 2014.
As of late 2024, the W06 holds several all-time Formula One statistical records: the highest percentage of available points scored in a season (86.04 percent), the highest percentage of podium finishes in a season (84.21 percent, 32 from 38 entries), the most 1-2 finishes in a season as a proportion of races held (63.15 percent), and the highest percentage of front-row lockouts in a season (78.94 percent). It initially also held the records for most points, wins, poles, and podiums in a single season, all of which were subsequently surpassed by its successor.
At the Hungarian Grand Prix, Mercedes added "#JB17" to the nosecone as a tribute to Jules Bianchi, who had died from injuries sustained in the 2014 Japanese Grand Prix. The gesture was widely acknowledged as among the more respectful livery modifications of the season.
The W06 proved that the W05's dominance was not circumstantial. By replicating — and in several categories exceeding — the statistical benchmarks of its predecessor, it confirmed that Mercedes had established structural advantages in both power unit technology and chassis design that would sustain the team through multiple regulatory cycles. Hamilton's third title drew him level with Ayrton Senna and moved him closer to Michael Schumacher's all-time record.