Lamborghini Sián FKP 37: The Lightning Bolt

The Lamborghini Sián marked the brand’s bold entry into hybrid supercar territory, combining the legendary naturally aspirated V12 with cutting-edge supercapacitor technology. As Lamborghini’s first hybrid road car, the Sián represented a technological bridge between the traditional naturally aspirated supercar era and the electrified future—while remaining, in every important respect, a Lamborghini in full.

The name itself sets the tone. “Sián” is the Bolognese dialect word for “lightning bolt”—direct, violent, instantaneous. It is also, appropriately, the primary quality that distinguishes the supercapacitor hybrid system from the battery-hybrid alternatives: supercapacitors discharge and recharge like a lightning strike, instantly and completely, rather than the sustained current flow of a chemical battery.

Historical Context: Why the Sián Existed

Understanding the Sián requires understanding where Lamborghini stood in 2019. The Aventador, then approaching the end of its second decade in production, still used a naturally aspirated V12 at a time when the entire industry was pivoting toward turbocharging and hybridization. Ferrari’s SF90 Stradale had demonstrated that a million-euro hybrid supercar could achieve 1,000 horsepower and find ready buyers. McLaren was developing the Speedtail. Bugatti had the Chiron.

Lamborghini’s engineers had been working on hybrid technology for several years—the Asterion concept of 2014 was a public preview of their thinking—but were committed to finding an electrification solution that enhanced rather than diluted the V12 driving experience. The conventional lithium-ion battery approach used by Ferrari carried a significant weight penalty and required dedicated thermal management systems that complicated packaging. Lamborghini’s engineering team, under the direction of CTO Maurizio Reggiani, pursued a different path: the supercapacitor.

The Sián was the production debut of this technology—and because Lamborghini understood they were introducing an unproven approach, they built it in the most exclusive possible context. With only 63 units produced (plus the prototype retained by Lamborghini), the Sián was never a commercial product in the conventional sense. It was a proof of concept, a technology demonstrator, and an exclusive collector’s item simultaneously.

Hybrid Innovation: The Supercapacitor System

The Sián was powered by Lamborghini’s 6.5-liter naturally aspirated V12 engine producing 785 horsepower, augmented by a 34 horsepower electric motor powered by supercapacitors. The total system output reached 819 horsepower, making it the most powerful Lamborghini road car at the time of its launch.

The electric motor is integrated directly into the 7-speed ISR (Independent Shifting Rods) automated manual gearbox—the same single-clutch transmission used in the Aventador—sitting between the engine and the differential. Its physical positioning within the gearbox means it can provide torque assistance during gear changes, filling the brief power gap that the single-clutch mechanism creates when changing gears. This is the Sián’s single most important dynamic contribution: the notoriously harsh, jarring shifts of the Aventador’s ISR transmission become fluid and connected, because the electric motor provides continuous drive torque through the interruption.

Supercapacitor Technology: The Science Behind the Lightning

Unlike traditional lithium-ion batteries, the Sián used supercapacitors for energy storage—and the distinction matters enormously.

A lithium-ion battery stores energy through chemical reactions: lithium ions move between electrode materials, releasing or absorbing electrons in the process. This chemistry is effective for high energy density (storing large amounts of energy in a given volume and weight) but is relatively slow: charging and discharging a battery involves managing the rate of chemical reaction, which cannot be accelerated beyond certain thresholds without damaging the cells.

A supercapacitor stores energy electrostatically rather than chemically, using two conductive plates separated by an electrolyte. There is no chemical reaction—energy is stored as an electric field between the plates. This means supercapacitors can charge and discharge nearly instantaneously, limited only by electrical resistance rather than chemical kinetics. They are also far more durable than batteries: where a lithium-ion cell degrades with each charge cycle, a supercapacitor can sustain hundreds of thousands of charge-discharge cycles without meaningful performance degradation.

The trade-off is energy density. A supercapacitor stores far less energy per kilogram than a lithium-ion battery—the entire Sián supercapacitor system, weighing just 34 kg, contains approximately 0.5 kWh of usable energy. This is enough for perhaps 200-400 meters of purely electric propulsion—essentially nothing in EV range terms. But for its intended purpose—instant torque augmentation and gear change smoothing on a 200 mph supercar—it is precisely correct.

The complete electric system in the Sián, including the supercapacitor, motor, electronics, and associated components, weighs just 34 kg. A comparable lithium-ion battery pack storing enough energy for meaningful electric-only range would weigh several hundred kilograms. For a car where every kilogram of added weight is visible in dynamics, the supercapacitor’s minimal mass penalty was decisive.

Design Evolution

The Sián’s design evolved Lamborghini’s aggressive styling language with hybrid-specific elements, while also pointing clearly toward what would become the Revuelto’s visual vocabulary. Designer Mitja Borkert’s team, working in 2018-2019, produced a car that was visually distinct from the Aventador it was based on while clearly sharing its proportions and basic architecture.

Key design innovations that would influence subsequent Lamborghinis:

• Y-shaped taillights in their most prominent form yet, integrating the light signature with the aerodynamic rear diffuser
• Hexagonal exhaust placement and exposed mechanical elements at the rear, previewing the Revuelto’s approach
• Integrated active aerodynamics with minimal visible external mechanisms, managing downforce through carefully shaped body surfaces
• Gold accents (the customer could specify color, but gold trim was featured prominently in the reveal car, reinforcing the Sián’s special status)

The scissor doors, Lamborghini’s signature since the Countach, were of course present—as they are on every Lamborghini flagship.

Aerodynamic Excellence

The Sián’s aerodynamic development was conducted with the full resources of Lamborghini’s wind tunnel program and computational fluid dynamics capability. Unlike the Aventador SVJ with its ALA active aerodynamics system, the Sián used passive aerodynamics managed through careful body shaping.

The front splitter, side sill extensions, and rear diffuser work together to generate significant downforce at speed while maintaining manageable drag for high-speed stability. The rear deck’s shape, combined with the integrated spoiler lip and the upward-directed exhaust placement, creates a rear aerodynamic package that provides stability approaching the car’s 350 km/h theoretical maximum speed.

Active elements are subtle: the engine air intakes in the rear haunches adjust their opening area depending on cooling demand and speed, mimicking the “bat wing” feature of the Murciélago in a more aerodynamically integrated form.

Performance Metrics

The Sián’s performance figures reflect both the power of the hybrid system and the limitations of the Aventador platform it was built on:

• 819 horsepower combined (785 hp from the V12, 34 hp from the electric motor)
• 0-62 mph in 2.8 seconds — same as the Aventador SVJ, reflecting the platform’s traction limits
• Top speed of 350 km/h (217 mph)
• Electric boost: The supercapacitor system delivers maximum electric torque (approximately 200 Nm) instantly at the moment of acceleration, particularly beneficial at low-to-medium engine speeds where the V12 is still building through its power band

Production Exclusivity and the Naming Convention

Limited to just 63 units worldwide (plus one prototype retained by Lamborghini), each Sián was delivered with a unique specification and color combination. The number 63 was not arbitrary: it referred to 1963, the year of Lamborghini’s founding by Ferruccio Lamborghini in Sant’Agata Bolognese.

The full name—Sián FKP 37—carries an additional tribute: the initials FKP stand for Ferdinand Karl Piëch (Ferdinand Karl Piëch in German), the legendary Volkswagen Group chairman and engineer who oversaw Audi’s acquisition of Lamborghini in 1998 and whose vision transformed the company from a financially precarious artisan manufacturer into a commercially successful global brand. Piëch died in September 2019, just weeks before the Sián’s public unveiling at the Frankfurt Motor Show. The naming was Lamborghini’s tribute to his legacy.

The roadster variant, produced in a run of 19 units (a number chosen to mark the 19-unit limit of the Reventón Roadster series), is equally exclusive. Its open-top configuration required substantial chassis reinforcement—carbon fiber additions to the windscreen frame and door sills—to recover the rigidity lost by removing the roof structure.

Cultural Impact and Technology Transfer

The Sián proved three things simultaneously. First, that Lamborghini could embrace electrification without losing the emotional connection of naturally aspirated engines—the V12 remained dominant, unchanged and unapologetic. Second, that supercapacitor technology worked in a real-world road car context, delivering the benefits of hybrid assistance without the weight penalty of battery technology. Third, that the market for ultra-exclusive, technically ambitious limited-edition Lamborghinis was robust: all 63 units sold before the car was shown to the public.

The technology transfer from the Sián to subsequent Lamborghinis was significant. The Countach LPI 800-4 (2022) used the identical supercapacitor system. The broader hybrid learnings from the Sián program—integration strategies, electronic management systems, driver interface—informed the development of the Revuelto’s more comprehensive HPEV system, even as the Revuelto chose lithium-ion batteries over supercapacitors due to the greater energy storage required for meaningful electric-only driving.

Legacy: The First Step Into a New Era

As Lamborghini’s first hybrid supercar, the Sián demonstrated the brand’s commitment to innovation while honoring its V12 heritage. The supercapacitor technology and hybrid performance set a new standard for electrified supercars in terms of power delivery quality rather than raw output figures.

The Sián FKP 37 wasn’t just a car; it was a technological statement—a declaration that Lamborghini’s path into the electrified era would be defined by their own engineering convictions rather than borrowed solutions from mainstream automotive technology. In that sense, it embodied everything that distinguishes a Lamborghini from the crowd: a willingness to pursue the more interesting, more difficult, more Italian path, regardless of what the conventional wisdom recommends.

Every Lamborghini that has followed—the Countach LPI 800-4, the Revuelto, the Temerario—carries some part of what the Sián pioneered. It was, in the most literal sense, the lightning bolt that illuminated the direction ahead.