THE Citroën is a very different kind of car. So much so, that it is regarded almost with awe.
It is a complicated car: one glance under the bonnet is
sufficient to prove that point: the four-cylinder motor (in full
two-litre form on the new DS models) is dwarfed by a host of
auxiliaries needed for the power brakes, power steering, Hydropneumatic
suspension and heating system. Pumps, tanks, lines and hoses areeverywhere.
It is also a totally-different kind of car to drive. It
floats along as no other car can, and its adjustable, self-levelling
suspension plays the strangest up-and-down tricks, which are
disconcerting until the driver becomes accustomed to them.
UP AND DOWN
Normal suspension position gives a ground clearance of 6.5 in. By
lifting the lever (on the floor next to the driving seat) one notch, it
rises easily to give 8-in. clearance, and at the top notch floats up to
give another 3 in. of clearance for road obstacles. In this form, the
suspension is pumped up and harsh-riding.
At the other end of the scale, the suspension can be
lowered totally by dropping the lever to the floor, till the car rides
on the stops. At this point there is no suspension at all and the ride
becomes impossibly hard and bouncy.
These ups and downs, as a matter of interest, have no
material effect on performance, as this is a car which is aerodynamic
all over, even to smooth contours along its underbody, so frontal area
is unaffected by gross height.
Do owners ever use this variable road clearance ability? In our view, it is an over-complication which is not really justified.
HOUSED HEADLAMPS
On the DS models, twin headlamps are used — 5-in. high beam, and 7-in.
low beam. On the latest “Three” model — announced a few months ago in
the Republic — these lamps are enclosed in sleek plastic housings, and
this change is accompanied by a revision of frontal valance and bumper
design to give an even more futuristic appearance.
While this jet-shaped nose has a good aesthetic and
aerodynamic appearance, it is a sobering fact that the Citroën has a
quite massive gross frontal area — 29.4 sq. ft.
INTERIOR FEATURES
The interior on the new model remains roomy and comfortable, with a
particularly-gratifying amount of headroom and legroom, owing to the
long passenger compartment housed inside the very long wheelbase.
Comparing the DS layout with that of the earlier ID
models, the instrument panel has been made more involved by the
addition of extra switches. There is a group of six unmarked switches
at centre. Two operate wipers and washers, but we were unable to fathom
the function of the other four!
While it has a heater and comfortable seats, the car
does not have much in the way of luxury equipment: no cigar lighter, no
reclining seats, and only a very small glove box.
MECHANICAL CHANGE
An important mechanical improvement on the “Three” is that the overall
hydraulic system has been revised to enable Hydropneumatic suspension
pressure to bleed back into the braking system, in the event of the
main hydraulic pressure pump failing.
This means that even if the pressure pump should fail,
the brakes remain pressurised. On previous models, a pump failure could
lead to loss of brake boosting, leaving the driver with only physical
pressure control for the brakes.
In other respects, the “Three” remains as for the DS
model: 1,985 c.c. of efficient motor, producing 90 b.h.p. S.A.E. on a
compression ratio of 8.75 to l.
DIFFERENT ENGINE
This is a bigger engine than that used in the ID models, and also quite
different in specification. Where the 1,911-c.c. engine had a very long
stroke (100 mm.) the DS motor is almost square, with a bigger bore. It
uses hemispherical combustion chambers and pistons with recessed domes
to give a high c.r., and suffers no problems at sea level on our
indifferent “premium” fuel.
The engine has five main bearings and is a smooth-running
unit. It is paired with such efficient transmission that it is all but
impossible to guess that this is a front-wheel-drive car.
PERFORMANCE FACTORS
The new, bigger engine is more powerful, but the DS models are also
considerably heavier than the IDI9, and actually have a slightly
less-favourable weight-power ratio (35.7 lb./b.h.p. net, against 35.4
for the old model).
There has also been a substantial change in gearing,
brought about by the higher revs. peak of the new engine (5,500, as
against 4,500) and a change to a 4.375 to 1 final drive ratio in place
of the 3.875 used in the ID models.
So where the ID was geared for 23.0 m.p.h./1,000 r.p.m.
in the indirect-drive top, the DS turns at 20.5 m.p.h./1,000 in the
same over-drive ratio.
The new model is still nominally overgeared (very much so) but this is based only on its increased engine range.
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