The Lamborghini Sian’s hybrid tech was never designed for series-production cars.
With its striking looks and revolutionary hybrid powertrain, the Lamborghini Sian was one of the standout debuts at the 2019 Frankfurt Auto Show. Powering the limited-edition supercar is the Aventador SVJ's 6.5-liter V12 unit uprated to produce 774 hp combined with an innovative 48V hybrid system that adds an extra 34 hp. This setup brings the total output to 819 hp, making the Sian the most powerful and fastest Lamborghini ever made. It effectively previewed the next-generation Aventador hybrid.
What sets the Sian's hybrid system apart is its lithium-ion supercapacitor, which is three times more powerful than a battery of the same weight and delivers engine torque directly to the rear wheels. During braking, the system uses the inertia to recharge the capacitor. This energy is stored in an instantly-available power boost of up to 81 mph and provides increased torque and instant acceleration in low gears. But according to CarSales, the new Aventador won't be equipped with the Sian's supercapacitor.
The reason? As Lamborghini chief technical officer Maurizio Reggiani explains, this lightweight system is focused on improving power rather than range, which isn't suitable for a series-production car. "With a supercapacitor you can accumulate in the same space three times as much power as a battery. However, it's clear that at the moment a supercapacitor cannot guarantee that you have the range to do even 5-10 km (3-10 miles) in full-electric mode. The storage is not enough."
"For the Sian, given that it was the first application of hybridization in a Lamborghini it was more important to say what is the DNA of a supersport car. So, the focus was to improve the performance while being as light and compact as possible. The answer to this was the supercapacitor. With a car that sells in the volumes that the Aventador does, there is another point that you need to take in consideration that relates to CO2 emissions. If you want to attack CO2, you need to have a battery that guarantees a certain range of full-electric mobility. With the supercapacitor as it is today, you cannot have this."
Instead, Reggiani said the Aventador successor is likely to feature a plug-in hybrid with a lithium-ion battery. This will inevitably add extra weight, but it's a necessary evil to meet ever-stricter emissions targets. But while there were concerns the Aventador may lose Lamborghini's sweet-sounding V12 in favor of a V8, Reggiani assures this won't be the case. Phew.
"If we talk about the Aventador, this is our flagship, and with the naturally aspirated V12 it represents the perfect marriage," he said. "Lamborghini was born with the V12, and this the only engine that has remained throughout the entire history of the brand. It must remain also for the future." The Huracan's future replacement, on the other hand, may be fitted with a V10 or a twin-turbo V8 according to Reggiani.