Jeep Grand Cherokee SRT8 2012 Owner's Manual page 458

456 STARTING AND OPERATING
Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, use
the AutoStick feature to select a lower gear.
NOTE: Using a lower gear while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. Refer to the "Main-
tenance Schedule" for the proper maintenance intervals.
Electronic Speed Control – If Equipped
− Do not use in hilly terrain or with heavy loads.
− When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
− Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
− City Driving
When stopped for short periods of time, shift the trans-
mission into NEUTRAL and increase engine idle speed.
− Highway Driving
Reduce speed.
− Air Conditioning
Turn off temporarily.