There might be a special tool dipstick as with the transmission. I don’t know if there’s one you can keep in the dipstick tube.

From ‘05 or so MBs have engine oil dipsticks again.

FWIW, I haven’t read in this forum that anyone’s run out of oil in these engines without the dash display alerting of low oil quantity.

Sixto
98 E320s sedan and wagon
02 C320 wagon