Ferrari FXX K

The FXX K at a glance

How the FXX K differs from the LaFerrari

The FXX K uses the LaFerrari's carbon monocoque and hybrid layout, but Ferrari developed it without the limits of road homologation or racing rules. The V12 received new camshafts, mechanical tappets in place of hydraulic ones, polished intake manifolds and an exhaust without silencers. Output rose from the road car's 708 kW to 772 kW, an increase of 64 kW, and the electric motor was turned up to 140 kW.

Aerodynamics changed most. The rear has two tail fins with an adjustable spoiler between them, the lights are new and the bumper and diffuser are larger. Launch figures put the length at about 4,895 mm and the width at 2,051 mm, while height and wheelbase stayed the same. Downforce reached 540 kg at 200 km/h. By our calculation, the car carries about 1.5 kg of dry weight per kW, against about 1.8 kg per kW for the road-going LaFerrari. The road car's history and figures are covered on our LaFerrari page.

HY-KERS and the Manettino modes

The hybrid system works as a performance tool rather than for economy. A four-position Manettino on the steering wheel lets the driver choose how the battery and motor are used:

The car runs on Pirelli slick tyres with sensors that measure longitudinal, lateral and radial acceleration as well as temperature and pressure. These data feed the traction control system and Ferrari's development engineers. Carbon-ceramic brakes, 19-inch front and 20-inch rear wheels and a cabin with carbon bucket seats complete the package.

The XX Programme: how ownership works

Buying an FXX K did not mean taking it home. The cars are part of Ferrari's Client Test Driver programme: owners take part in a calendar of track events organised by Ferrari, while the factory stores, transports and maintains the cars. Each outing produces telemetry that Ferrari uses to develop its road and racing cars. The FXX K followed the FXX of 2005, based on the Enzo, and the 599XX.

Ferrari sold all 40 cars to invited clients, and press reports put the price at about 2.5 million euros in 2014. The car has no road homologation, and Ferrari never intended it for competition.

FXX K Evo: the 2017 upgrade

Ferrari presented the FXX K Evo at the Finali Mondiali at Mugello in 2017. Ferrari offered it both as a kit for existing XX cars and as a limited number of new cars, and it extended the programme for two more years.

Additional downforce came from a reworked front bumper (about 10 %), an enlarged rear wheel-arch vent (about 5 %) and vortex generators under the floor, which account for about 30 % of the gain. Ferrari described the Evo's aerodynamics as close to those of its GT3 and GTE racing cars. Development took about 5,000 km of test running and 15,000 km of reliability testing.

How the FXX K compares with other track hypercars

The road-going McLaren P1, the FXX K's closest technical rival, was built in a far larger run of 375 cars; see our McLaren P1 page. Compared with today's road cars, the FXX K would still rank near the top of the most powerful cars and among the most powerful supercars.

The FXX K's place in Ferrari history

The FXX K showed how Ferrari uses its wealthiest clients as development partners: Ferrari designed the programme to collect data for future road and racing cars, including later hybrids such as the SF90 Stradale. For collectors, it remains one of the rarest modern Ferraris, and the programme structure means most cars have a fully documented history at the factory. The wider story of the brand is in the history of Ferrari, and all models are listed in the Ferrari catalogue.