Re: T-5 towing (wdunlop)
This depends greatly on the trailer.
There are a number of very important factors on how well a trailer tows. One of the most important is tongue weight - too much or too little and you will have a white knuckled journey. However, a properly set up trailer with 2,200 lbs should be no issue.
I have towed my 3,700 lb boat with no issues (on level ground, and in good weather). The trailer has tandem axles, surge brakes, is perfectly balanced. As a result, it tows very well, and the XC90 2.5T handles it well (although I worry about the longevity of the tranny). There have been several other owners who have reported similar results over the years. There was also a recent thread where someone posted that they were not pleased with their XC90 towing a pair of jet skis. I would suspect that the jet ski trailer is single axle, with no brakes, and is putting more of the work load on the tow vehicle than my boat trailer does.
As for the 2.5 and 5 speed - this motor makes a lot of low end torque, and does better than you would expect. However, when towing, my gas mileage was horrible - 9 to 11 MPG on level ground, at 55 MPH.
While I have found the XC90 does a decent job towing, I don't think I would buy an XC90 if I was planning on doing a lot of towing. I tow only on occasion, on level ground, in good weather, and only for moderate distances.