FIRST, LET’S UNTANGLE the spaghetti of that name. The Sián is not a tribute to Lamborghini’s distant Welsh cousin, but rather the word for ‘lightning’ in Bolognese – an eminently suitable moniker for the Italian company’s dazzling new hypercar.

A flash in the pan? Obviously not because despite the pandemic, Lamborghini sold all 19 open-cockpit Sián models to extremely well-heeled hypercar aficionados last year, paying around £2.5m a piece for the pleasure.

Now the similarly priced coupé, which runs to a modest 63 examples (Lamborghini was founded in 1963), has also gone in the blink of eye, or at least as fast as its 0-62mph time of 2.8 seconds.

This outrageous hybrid boasts 808bhp, races to an astonishing 218mph, and looks like nothing else on the planet.

It is quite simply the maddest motor I’ve encountered in ages and everything you’d hope to experience from Lamborghini.

It doesn’t matter that the Sián is wildly impractical, too fast to fully appreciate on a public road without losing your licence, and definitely not suited to the current economic climate – Sián simply screams wealth – because a Sián is quite simply not of this world.

I’m driving the one and only demonstrator model here in Britain, where Lamborghini has taken over the Millbrook Proving Ground in Bedfordshire. It’s a freezing February morning, and I’m just grateful it’s not the roofless roadster.

In a few days’ time, it will be flown back to Italy and put on display in Lamborghini’s own museum. There it will feel completely at home alongside equally mind-bending models, including the LM002 ‘Rambo Lambo’ truck, the dramatic Espada and bonkers Reventon.

This is a once-in-a-lifetime drive, but I have to follow a ‘modest’ Lamborghini Huracán, admittedly driven by racing driver Jack Bartholomew, on a carefully orchestrated route.

Lamborghini is rightly anxious that its one-off demo isn’t stuffed into an Armco barrier. But I’m still allowed to have enough fun to appreciate that the Sián clearly returns incredible acceleration and agility for such a big car.

The fastest Lamborghini ever doesn’t need coaxing. It’s almost impossible to drive slowly and on a banked, bowl test circuit sits at 130mph like it was purring up the M4 in the slow lane. There are tons more revs left, the engine is barely breaking into a sweat.

It is quite simply the maddest motor I’ve encountered

Under the rear engine cover sits an uprated 6.5-litre V12 from the Aventador – except the Sián has the added benefit of a 48-volt e-motor, which together deliver a staggering 808bhp.

Key to this is a highly advanced regenerative braking system, especially developed for the car. Every time the brakes are applied, the Sián’s energy storage system is fully charged up.

That energy is instantly available as a power boost, allowing me to draw immediately on increased torque when accelerating up to 75mph, when the e-motor automatically disconnects.

Compared to the V12-powered Aventador, the extra few horsepower is clearly noticeable, sling-shotting the Sián away from a standstill at ridiculous speed. Thankfully, the hypercar still sounds like a proper old-school Lamborghini
– it just wouldn’t be a Lambo otherwise.

The unit is mounted in the gearbox and energy is produced via a cool-sounding supercapacitor, which dispenses with the need for a heavy lithium-ion battery, but can discharge and recharge energy at the same rate.

The supercapacitor – I can’t say that word enough – is located in the bulkhead, between the cockpit and engine of the Sián, helping to ensure perfect weight distribution.

Sián isn’t a plug-in hybrid and can only use electric power for low speed parking. The mildest of mild hybrids, this flamboyant Lambo really wasn’t created to win over environmentalists.

Thanks to the use of lightweight materials, the Sián’s power-to-weight ratio is even better than the ultra-extreme Aventador SVJ. As Lamborghini’s first foray into hybrid propulsion, it’s quite a statement.

And while the innovative powertrain and titanium intake valves are genuine talking points in their own rights, the Sián is mostly about performance and the astonishing styling. Forget practicalities, this is quite simply the most insanely powerful and mesmerising hypercar.

“With this car, we set ourselves the challenge of creating the best hybrid solution for a Lamborghini super sportscar,” explains chief technical officer, Maurizio Reggiani.

“Lamborghini is inherently a rule breaker, a challenger, always pushing what is possible to find a better solution. With Sián, we are setting new rules in new technologies – instead of just following existing methods.”

Lamborghini is inherently a rule breaker, a challenger, always pushing what is possible

Even so, the Sián’s styling uses plenty of design cues from the past. The front end is dominated by a carbon-fibre front splitter and Y-shaped headlights – a feature that was originally designed for the Terzo Millennio all-electric concept car back in 2017.

The Y shape pops up again for the door air inlets, and harks back to the iconic Countach of the 1970s. In the roof, a Periscopio tunnel – a feature originally installed in the Countach because of its appalling rear visibility – links with the slats of the rear engine cover.

And just look at those back-light clusters, plus the aerodynamic airstreamers fixed atop the rear wings. Hexagon shapes are sprinkled everywhere, from the twin exhaust pipes and door mirrors, to the rear lights and instrument binnacle. The Sián really is madness from every angle.

“Not only does the Sián deliver an engineering tour de force, it augments the potential for us as a supercar brand for tomorrow and decades to come with hybrid cars,” says Reggiani. “It is the first step in Lamborghini’s route to electrification and expedites our next-generation V12 engine.”

Inside, the low-slung cabin is similar to the Aventador SVJ. Expect rock-hard seats, Lamborghini’s trademark, flip-top start button and some typically well-hidden and infuriating wheel-mounted indicator buttons.

If your Sián needs to make more of a statement, Lamborghini also offers the ultimate road-sea combo. A matching speedboat built by Tecnomar is powered by TWO V12 engines producing 4,000bhp and finished in the same paintwork as the car.

Just don’t expect to see that particular pair in Bedfordshire any time soon.

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