2007 Chrysler 300 Owner Manual - Page 308

308 STARTING AND OPERATING NOTE: Using the "3" range while operating the vehicle under heavy operating conditions will improve performance and extend transmission life by reducing excessive 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. See Schedule "B" in section 8 of this manual for transmission fluid change intervals. 7 - Pin Connector NOTE: Check the automatic transmission fluid level before towing. Towing Tips - Electronic Speed Control (If Equipped) − Don't 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. Towing Tips Before setting out on a trip, practice turning, stopping, and backing the trailer in an area located away from heavy traffic. Towing Tips - Automatic Transmission The "D" range can be selected when towing. However, if frequent shifting occurs while in this range, the "3" range should be selected.