Jeep 2004 Grand Cherokee Owner's Manual page 257

The best time to check the engine oil level is about 5
minutes after a fully warmed engine is shut off or before
starting the engine after it has sat overnight.
4.0L Engines
MAINTAINING YOUR VEHICLE 257
4.7L Engines
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level between the MIN and MAX or ADD and
SAFE markings on the dipstick. Adding 1 U.S. Quart
(0.95L) of oil when the reading is at the MIN mark will
result in a MAX reading on these engines.
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