Hydractive 2 Suspension - CITROEN XM Internet Reference

Suspension

69 Hydractive 2 suspension

69 Hydractive 2 suspension
All of the foregoing might be true of the Mk 1 XM but it is certainly _not_ true of Hydractive 2 suspended
cars. I say might because although I have never driven a Mk 1 car, those road tests I have read make
no mention of these phenomena - see Jints comments below.
On the Hydractive 2 cars, there is no subjective difference in ride quality at all between Normal and
Sports settings - both offer a level, smooth ride with very little body roll. Where there is a difference
between the two settings is in the handling - in Normal mode it is typical big Citroen - understeer (albeit
slight). In the Sports setting, handling becomes more neutral (although understeer still occurs in
extremis) and the steering feels sharper with more precise turn in.
The XMs ride is not perfect - it still doesnt like short frequency undulations or sharp discontiniuties in the
road surface such as are to be found on some British motorways which are surfaced with enormous
great concrete slabs. There is a section of road on my way home from work over which the XM feels
very choppy. Driving my wifes non-Hydractive Xantia over the same stretch was a revelation - the
Xantia was much smoother. However, the Xantia rolls much more in the corners and understeers far
more strongly than the XM, all of which conspire to make the Xantia significantly harder work to drive
quickly.
Other oddities with the XM are its propensity to adjust its attitude when stationary in traffic queues, the
transmission of road noise into the cabin - though whether this is down to the low profile tyres or not is
a moot point - and a slightly harsh low speed (below 50mph/80 kph) ride - but then every
hydropneumatic Citroen suffers from this to a greater or lesser degree.
The XM is not however the latest iteration of the hydropneumatic system - that honour belongs to the
Xantia Activa and the following comments are based on one test drive of about 15 minutes duration a
year or so ago. The Activa felt just like the XM but without any noticeable body roll. As a drivers car, it
has few peers but I suspect that passengers would find it less satisfactory since they will be thrown
around the interior of the car due to much higher lateral G forces than are comfortable or are likely to be
found in a more conventional vehicle. The problem is that the high levels of grip coupled with the lack of
roll and excellent handling encourage press-on motoring. Certain aspects of the Activas ride were
worse than that of the XM - low speed ride was harsher and the attitude adjustment was even more
noticeable including as it did both lateral and diagonal rocking accompanied by hissing when stationary.
Road noise seemed more marked too.
I believe that Citroen were of the opinion that you can get away with a very soft ride on cars with
(relatively) low performance. However, cars with high performance must have the handling/ride
dichotomy biased in favour of handling and this is what happened with the faster CXs and BXs. Where
the Mk 2 XM scores is that it provides a better reconciliation of these two conflicting requirements than
almost any other car. On the Activa, the balance is tipped slightly closer to the handling end of the
equation.
And Jint Nijman added
98 Citroen XM Internet Reference Version 1.0
3/3/99