McLAREN MP4/21 Mercedes

   Finally back at the top, Team McLaren in 2006 had to confirm the strong performance shown in 2005 with the MP4/20, which, in the hands of Kimi Räikkönen, battled Renault’s Fernando Alonso for the championship right up to the end. The British team’s new car was the MP4/21, the last McLaren designed under Technical Director Adrian Newey before his move to the newly formed Red Bull Racing team. The team led by Ron Dennis remained virtually unchanged from 2005: in addition to the aforementioned Newey, there were chief car engineer Tim Goss, supported by technical director Paddy Lowe and executive engineering director Neil Oatley. Peter Prodromou headed the aerodynamics department, Mike Coughlan was the chief designer, and Steve Hallam served as head of race engineering, alongside Norbert Haug, present in the garage as Mercedes’ vice president for sporting activities. This group of engineers formed a formidable team, with as many years spent in research departments as on the racetrack.

McLAREN MP4/21, Kimi Räikkönen
Imola, San Marino GP 2006 

   The McLaren MP4-21 was an evolution of the previous season’s car, though significantly different, with 90% of its more than 11,500 components modified compared to the 2005 MP4/20. The chassis and general lines of the new car largely mirrored those of its predecessor, though the nose once again featured the distinctive “needle” design first introduced by Newey on the MP4-19 in 2004. The front wing was low, short, and narrow, with a spoon-shaped central section similar to that of the MP4-20. Behind the front wheels were split bargeboards, followed by shorter sidepods with a hollowed lower section and triangular air intakes. The introduction of new V8 engines allowed for smaller cooling masses and thus smaller side intakes, providing significant aerodynamic advantages. In the upper section, new chimney-style outlets curved outward, integrating high-mounted exhausts. A series of transverse slits appeared on the sidepods, echoing the design introduced by the Renault R25.

McLAREN MP4/21, Kimi Räikkönen
Montecarlo, Monaco GP 2006

   In front of the rear wheels were several refined aerodynamic elements, including fins, spoilers, and vertical strakes. The characteristic “horns” above the cockpit remained, improving airflow efficiency to the rear wing, and an additional aerodynamic profile was placed near the rear light. The rear wing endplates had a rounded upper-rear corner and a series of horizontal slits, while their lower edges followed the wheel’s curvature. The rear end was closed off by the mandatory crash structure, which also served an aerodynamic purpose. As for the suspension, the front adopted a push-rod layout with split lower mounts anchored to the bottom edge of the chassis. The upper wishbone was raised and shaped like an airfoil that integrated the steering arm. The rear suspension featured an air intake element with an aerodynamic profile. A common feature was the suspension strut’s connection to the wheel hub. The brake calipers were angled, with a basket-type air intake that covered the disc and expelled hot air axially. Thanks to the ultra-light carbon and honeycomb aluminum monocoque chassis and the reduction of cooling mass, the new MP4/21 was practically a featherweight, allowing engineers to use 90 kg of ballast, adjustable for optimal balance while maintaining the regulatory minimum weight of 600 kg.

McLAREN MP4/21, Kimi Räikkönen
Magny-Cours, French GP 2006

   Due to regulation changes, Mercedes-Benz replaced the previous 3000 cc V10 engines with the new FO108S, a 2398 cc, 90° V8 with dual overhead camshafts and four valves per cylinder. The power unit weighed 95 kg, featured a 98 mm bore, and both the block and cylinder head were made of aluminum. Electronic management was handled by a McLaren Electronic Systems ECU, which, through the STAR2 System, allowed the engine to produce over 700 hp at 20,000 rpm, the maximum speed allowed by regulations. The engine lifespan was about 1,800 km, equivalent to two Grand Prix weekends. The gearbox was a McLaren-built, longitudinal, semi-automatic 7-speed unit with a carbon casing and “fast shift” system, featuring an auxiliary shaft enabling pre-selection of gears for instantaneous shifts. The engine change also required redesigning auxiliary systems such as cooling, intake, oil, and fuel delivery systems. For Prodromou and his aerodynamic team, it was also an opportunity to redesign the rear of the car. The MP4/21 was unveiled on January 23, 2006, at the McLaren Technology Centre, the company’s headquarters in Woking, Surrey, on a 500,000 m² site. It first hit the track at the end of January 2006 at the Circuit de Catalunya in Montmeló, featuring a historic papaya orange livery. In February, the official chrome livery was presented, along with new sponsors Emirates and Johnnie Walker, after the long-time partner West ended its collaboration during the 2005 season.

McLAREN MP4/21, Lewis Hamilton
Silverstone, private test 2006 September 

   The previous season’s drivers were confirmed: Finland’s Kimi Räikkönen and Colombia’s Juan Pablo Montoya. However, Montoya left the team mid-season to join Chip Ganassi Racing in NASCAR after retiring from the 2006 United States Grand Prix at Indianapolis. His seat was taken by the team’s test driver, Spaniard Pedro de la Rosa, while Britain’s Gary Paffett continued development work throughout the season. Despite scoring 110 points and numerous podium finishes, McLaren failed to win a race for the first time since 1996. Räikkönen finished fifth in the Drivers’ Championship, while the team placed third in the Constructors’ standings. After the season ended, former driver and two-time world champion Mika Häkkinen tested the MP4-21 with a view to a possible F1 comeback, though it never materialized. Future world champion Lewis Hamilton also drove the MP4-21 during his first official Formula 1 test in September 2006, before joining McLaren for the 2007 season. The MP4/21 chassis no. 3, driven by Montoya in the first three races and later tested by Hamilton, was sold for £2 million in early 2025, after being fully restored by McLaren in 2019.