Jeep 2004 Grand Cherokee Owner's Manual page 258

258 MAINTAINING YOUR VEHICLE
CAUTION!
Overfilling or underfilling the crankcase will cause
aeration or loss of oil pressure. This could damage
your engine.
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
If ANY of these apply to you, then change your engine oil
every 3,000 miles (5 000 km) or 3 months, whichever
comes first, and follow the maintenance recommenda-
tions in "Maintenance Schedule B."
If none of these apply to you, then change your engine oil
every 6,000 miles (10 000 km) or 6 months, whichever
comes first.
NOTE: Under no circumstances should oil change in-
tervals exceed 6,000 miles (10 000 km) or 6 months
whichever comes first.