Herringbone gears, front-wheel drive technology, hydraulic-pneumatic suspension system, etc.
1. Herringbone gears: Andre Citro?n bought out the invention patent for herringbone gears and applied them to the transmission systems of Citro?n cars to improve the transmission efficiency and performance of the vehicles.
2. Front-wheel drive technology: Andre Citro?n used front-wheel drive technology for the first time when designing a car, which transmits the engine's power to the front wheels, making the vehicle's driving more flexible and stable.
3. Hydraulic-pneumatic suspension system: Citroen cars adopt the hydraulic-pneumatic suspension system invented by André Citro?n, which provides a more comfortable and stable suspension effect through the linkage of hydraulic and pneumatic pressure.