Towing is easier on a manual tansmission. Most or some (well especially older vehicles) automatics will have a tendancy to shift in and out of overdrive more often than normal during towing, due to the additional drag and weight of the boat and trailer. Except in the case of larger vehicles with huge towing capacities, this heats up the transmission fluid more than normal operation. Check your owners manual for recommended towing practices. Some will suggest turning the overdride off (if function is available) or keeping the transmission selector in the next to highest gear (3 or 4). In either case this is preventing the transmission from making more frequent shifts.

A transmission cooler may be added by any competent mechanic and are available at all chain auto parts stores. The transmission fluid lines are routed to the front of the vehicle for cooling anyway making it a fairly easy modification that should cost less than $200. If you feel your vehicled is overworked, it's a fairly inexpensive insurance policy to have. Or, have your transmission serviced at the "Heavy use" interavals. Personaly we change the fluid more often.

Since the old days and "sport" vehivles were brought up...

Had great fun towing the spanking new '81 H16 with our '67 Camaro, 327ci/275hp. Wish we still had that little rascal. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />