2007 Chrysler Aspen Owner's Manual - Page 336

336 STARTING AND OPERATING If using a manual transmission vehicle for trailer towing, all starts must be in FIRST gear to avoid excessive clutch slippage. Towing Tips - Automatic Transmission The "D" range can be selected when towing. However, if frequent shifting occurs while in this range, the "TOW HAUL" feature should be selected. NOTE: Using the "TOW HAUL" feature 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 Towing Tips Before setting out on a trip, practice turning, stopping and backing the trailer in an area away from heavy traffic.