Externally, the car was a streamlined and refined evolution of the previous year's MP4/11, retaining a similar concept while incorporating improved aerodynamics. Mercedes-Benz supplied the engines for the third consecutive year of the Anglo-German partnership. The FO110E unit was replaced mid-season with the FO110F from the French Grand Prix onward, but neither variant proved sufficiently dependable in the hands of two drivers who had the pace to lead races.
One of the most significant technical developments of the MP4/12's season was the discovery of a device the team called "brake steer." Photographer Darren Heath, working for F1 Racing magazine, observed that the McLarens' rear brakes were glowing red in acceleration zones — an unusual location for heat build-up. Subsequent analysis of cockpit photography revealed a second brake pedal fitted to the car, which the driver could use to selectively apply braking force to one rear wheel. This allowed the driver to reduce understeer and control wheelspin when exiting slow corners, effectively steering the car with the rear brakes as well as the front wheels. Ferrari protested the system to the FIA, and it was banned from the start of the 1998 season, beginning at the Brazilian Grand Prix.
Coulthard gave the MP4/12 a winning debut by taking victory at the opening round in Australia, McLaren's first race win since losing Ayrton Senna to Williams, and also Mercedes' first Formula One victory since the 1955 Italian Grand Prix. The season that followed, however, became a litany of frustrated opportunities. Häkkinen retired from three separate races while running in the lead, all due to engine failures. The most painful of these came at the Nürburgring, where both cars retired with identical failures within a single lap of each other, costing the team a comfortable one-two finish. Coulthard also lost a likely victory at the Canadian Grand Prix when a precautionary pit stop for a clutch issue was made just laps before the race ended. He did win again at Monza, providing McLaren with their second victory of the year.
The season reached a dramatic conclusion at Jerez, where the championship was decided. After Michael Schumacher and Jacques Villeneuve collided, the McLarens circulated to the finish to claim a one-two result, with Häkkinen crossing the line first for his maiden Formula One victory. It was a significant moment: Häkkinen had been tipped as a future champion since he outqualified Ayrton Senna at the 1993 Portuguese Grand Prix, and the Jerez win provided the platform for his 1998 title-winning campaign against Schumacher.
McLaren finished fourth in the 1997 Constructors' Championship with 63 points.
The MP4/12 appeared in two distinct liveries during the season. Pre-season testing was carried out in an interim papaya orange scheme, honouring the traditional McLaren colour from the late 1960s and early 1970s. For the race season, the car was relaunched in a striking black and light silver livery to celebrate a new title sponsorship deal with West cigarettes, ending the long-standing red and white Marlboro livery that had adorned McLarens since 1974. The West logos were absent from the car at the French, British, and German Grands Prix due to local tobacco advertising regulations, replaced by a "double stars" graphic.
The MP4/12 occupies an important place in McLaren's history as the car that ended a prolonged victory drought and demonstrated the potential that would deliver back-to-back world championships in 1998 and 1999. Its most enduring technical footnote is the brake steer controversy, which prompted a specific regulatory ban and influenced subsequent thinking about driver aids in the sport.