Jeep Automobile Owner's Manual page 317

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.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Maintain
the oil level in the SAFE level range. Adding 1 U.S. Quart
(0.95L) of oil when the level is at the bottom of the SAFE
range will result in the level being at the top of the SAFE
range.
CAUTION!
Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
MAINTAINING YOUR VEHICLE 317
Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
• Day or night temperatures are below 32°F (0°C)
• Stop and go driving
• Extensive engine idling
• Driving in dusty conditions
• Short trips of less than 10 miles (16.2 km)
• More than 50% of your driving is at sustained high
speeds during hot weather, above 90°F (32°C)
• Trailer towing
• Taxi, Police, or delivery service (Commercial Service)
• Off road or desert operation
• If equipped for and operating with E-85 (ethanol) fuel
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