Opel Cascada Owner's Manual page 186

184 Vehicle care
Pull out the dipstick, wipe it clean,
insert it to the stop on the handle, pull
out and read the engine oil level.
Insert dipstick to the stop on the
handle and make half a turn.
Different dipsticks are used
depending on engine variant.
When the engine oil level has
dropped to the MIN mark, top-up
engine oil.
We recommend the use of the same
grade of engine oil that was used at
the last change.
The engine oil level must not exceed
the MAX mark on the dipstick.
Caution
Overfilled engine oil must be
drained or suctioned out.
Capacities 3 238.
Fit the cap on straight and tighten it.