In the mid-1990s, French engineers introduced the Activa version of their popular family model Xantia. At first glance, it was an ordinary hatchback, but under its sheet metal was an engineering marvel that still holds an unthinkable world record.
The Technology: Active Spheres Against Centrifugal Force
While standard cars use springs and shock absorbers, Citroën opted for hydraulic spheres filled with nitrogen and special oil (LHM). However, the Activa system went one step further. It had two additional hydraulic cylinders and a sophisticated electronic brain that measured the steering angle and speed.
The moment the car started to turn, the system instantly pumped oil into the corresponding cylinders to counteract the body's tilt. The result? The car remained perfectly horizontal, no matter how sharply you turned.
The most impressive proof of the power of this technology is the famous “Moose test“ (a test for sharply avoiding an obstacle). In 1999, the Citroën Xantia Activa passed through the cones at a speed of 85 km/h.
To understand the scale of this achievement: this speed is higher than that achieved by legends such as the Porsche 911 GT3 (997), the McLaren 675LT and even the Audi R8. For more than 20 years, no production car has managed to improve the record of this “ordinary” French family car.
The Feel: Like Riding a Magic Carpet
Driving the Activa is a surreal experience. While in a normal car your body leans to the side when cornering sharply, here you sit still as the car literally “bites” the asphalt. This not only improves stability, but also allows incredibly high speeds in corners without the tires losing contact with the road.
Why did it disappear?
Although it offered safety and stability from another dimension, the system was extremely complex and expensive to maintain. With ten hydraulic spheres and tens of meters of pressurized pipes, it required specific knowledge from the mechanics. With the advent of simpler electronic stability systems (ESP), Citroën decided to retire the hydraulics, leaving the Activa in history as the pinnacle of the French genius.
Interesting fact: The tires of the Xantia Activa wore much more evenly than those of standard cars, because thanks to the system, they always stepped with their entire surface on the asphalt, without "breaking" in a bend.