Why isn't hydropneumatic suspension used today?

I believe this type of system is still used with semis, and with the custom car crowd. Cars, trucks, and motorcycles that have been “bagged” use air pressure and bladders that raise the vehicle off of its rests and provide smooth suspension. Bagged custom truck in resting position. read more

Compared to a standard suspension, an HP is expensive and requires much maintenance. Adjustable shock absorbers have become available at reasonable prices. Today’s streets are better than the streets of the 50’s. Therefore most cars of today feature a stiffer suspension than in the early days. read more

Rolls Royce licensed the system from Citroen in 1965. Mercedes Benz tried its hand with air suspension, which used air pumps to increase the stiffness of the suspension, but in 1974 it introduced the 450SEL 6.9 with hydropneumatic suspension. Peugeot also used the system on the 405 in 1990. read more

This was 70 years ago. Today many car makers have air suspension available which can outpace an HP system. In fact a Mercedes E-class with Airmatic suspension is more comfortable than a Citroen C6. Compared to a standard suspension, an HP is expensive and requires much maintenance. Adjustable shock absorbers have become available at reasonable prices. read more