'What Car' Article

[citroenxm]

LOOK at the R25... Its Geourgeous!!! I LOVE it.. Oppppss um, I mean XM...


Those R25 seats look as comfy as XM Leather does.. I STILL want one!

[citroenxm]

Ren 25 was last tax till 2000.
The Saab Last tax'd till 2006
Lancia last tax will till 2001
The XM Cannot be found!

[casalingua]

Thanks for posting that. I will eventually get around to adding this data to the by now voluminous "Critical appraisal" section of the Wikipedia article. The most resonant problem with the XM is that one involving short sharp shocks. This means the car (as in my experience) simply hates pockmarked urban surfaces. Show it a rough gravelly road though and it simply glides over it. What an odd design flaw.

[White Exec]

. . . This means the car (as in my experience) simply hates pockmarked urban surfaces. Show it a rough gravelly road though and it simply glides over it. What an odd design flaw.

Must be something to do with that immaculate French tarmac, and maybe ploughed fields ?

More seriously, I presume it has something to do with the speed at which the suspension is capable of reacting. An undulation makes a quite different demand on the damping characteristics, compared with a sudden/instantaneous/vertical edge pothole or ridge.

The comparatively recent 2.5 suspension is pretty 'sporty' and controlled, compared to older Citroen standards. A late Xantia of mine used to crash about on sharp ridges, quite 'wooden' feel, and not a lot different from a coil-and-torsion-bar ZX I had for a year. In contast our '89 BX19RD would mop up anything, and had what I believe to be the last of the "long travel" suspensions. It was also Normal/Comfort at the raised suspension setting, only solid at fully up and fully down.

Wasn't it J.Clarkson who once pointed out the difference between Bentley and Rolls-Royce suspension? While the Bentley absorbed all the bumps admirably, the Rolls, with its few hundred pounds of additional weight, actually flattened them.

C.

[Dieselman]

Xm have smaller damper orifices and tighter damper valves to make the ride more sporty. iirc the frequency of damping is reduced from the 2.5Hz of the Ds doen to 1.5Hz.
This means the oil transmits more sharp shock.

[casalingua]

I read this review again and noted two things. One is that the review is consistent with all the other UK reviews I´ve studied. The car never came first in any test, no matter what the competition was. The other thing is the strange understanding the writers have of how cars are designed. The verdict in the article refers to "jelly-mould computer designs" as if computers had any active say in the appearance of a car. Even today computers are used only to create mathematical models and the parameters are set by engineers and designers. Cars are no more designed by a computer than by a pencil. They are designed with computers. Additionally, the odd way the XM has of dealing with sharp pavement irregularities leaves me wondering why Citroen tolerated such a design flaw. Urban roads are characterised by scabs, cracks and lumps; you´d expect the management of these annoyance would have been a minimum requirement. What led Citroen to let the car go into production with a flaw that essentially destroyed their USP´s credibility is beyond me. And finally, engines. The engines (and gearboxes) were the other weak link in the XM´s armoury. They were always described as underpowered and unrefined. The German skill at making refined engines with enough grunt has been a major reason their Mercs and BMWs are respected and sold for a high price. Is there a particular reason the French never grasped the importance of powertrains in selling desirable cars?

I´ve added this review to the huge compendium of contemporary criticism at the XM page at Wikipedia. Thanks for posting the page scans, by the way.

[russ92xmsed]

Is the XM suspension caught out by sharp shocks also due to it being a MacPherson set up rather than multi-link?

On the subject of car design, I studied Automotive design for my degree at Coventry Uni...so I have a little understanding of the design process of how a car comes about. It usually always starts with a team of designers coming up with highly conceptual ideas which, usually through a series of internal competitions, are refined and turned into a design that can be developed. Packaging and ergonomics dictate the whole design and then engineering & legislation sticks it's nose in too. Once the design is approved for further development, it is then modeled digitally using Alias computer software. The modelers then actually refine the design, even down to the finished body surfacing, interior design, almost everything of how it would look like...and amazingly accurate too. I believe the design then potentially takes two routes. It is either milled either in clay or plastics straight from the computer, meaning efficient and quick 3D modelling or it takes the Clay/buck route. Arguably the clay model has the touch of a human hand, something a computer will never be able to create and because of that has a more natural quality.
Then it is signed off for production and tooling is taken of the final accurate design model. I you have read the Black XM book, you'll understand. Not much has changed in that respect....Well that's a very simplistic edited version of how a car is designed anyhow.
Interesting piece of pointless info, the BMW 7 series of 1987 is in fact asymmetrical. The car was modeled in Clay, as usual, but wasn't modeled accurately ..so one side is very subtly different to the other. The BMW bosses liked the design so much, they took the measurements for the production tooling, straight from the clay model without checking. And that is how it stayed! So the Germans don't always get it right!

With regards to French power-trains being either underdeveloped or not quite hitting the mark, has to be down to the bean counters, or shear bloody mindedness! It is true, they have never really got it right...particularly with petrol engines. Good ...but not brilliant.

I still prefer French cars though. More soul and design flair!

Russ