CITROEN 2 CV4 1975 Owner's Manual page 20

MAINTENANCE
Levels
Checks and Topping up
1 Engine oil dipstick
The engine oil level, which must lie between the ends of the cut-out
on the dipstick, must be checked from time to time between oil
changes and, in particular, before any long journey.
The check should be carried out with the car as level as possible,
after the engine has been stopped for at least 10 minutes.
To top up, add oil without the level going above the top end of the
dipstick cut-out. The length of the cut-out is equivalent to 7/8 imp.
pints (0,5 litre).
Fig. 32
2 Engine oil filler pipe
Engine Oil Dipstick
In Summer, as in Winter, use "TOTAL Altigrade GT Spéciale
1 - Maximum
Autoroute 20 W 40" or "GTS 20 W 50" oil. If "TOTAL" oils are
2 - Minimum
not available, use equivalent grades of other reputable makes.
3 - Oil level reading
In very cold countries (temperatures often lower than -10C (14F),
use "TOTAL Altigrade GT Spéciale Autoroute 10 W 30" or "GTS
10 W 30" oil, or equivalent grades of other reputable makes.
Never use additives
Do not forget to tightly seal the oil filler cap.
3 Brake fluid reservoir