I want to have a tow bar installed on my 2004 Volvo XC 90 25 T AWD model. Do I need to put a new oil cooler? It has been suggested that this is absolutely necessary lest the vehicle heats up when towing.

 

Really depends on what you expect to tow and where. If you're going to pull something sizeable (ie heavy boat, camper etc) or you live in the mountains, then you should look into the components of the towing package many cars offer. Typically this is a larger oil cooler and transmission cooler. Also a good idea to know your car's towing capacity (some say 4000 lbs others say 5000?). My sense is more of the stress goes on the transmission than the motor - since you can drive conservatively (ie keep off the turbo boost, avoid high speeds (air resistance is the killer at speeds over 55-60). If you can't find a transmission and oil cooler upgrade, at a minimum you should do full synthetic fluids in the engine oil, and put in new clean synthetic fluid in the transmission and synthetic gear oil in the transfer case.