Hi Ian; I'm pulling a 16' fgrv with a 1995 Volvo 960 wagon
It is a six cylinder with a listed towing capacity of 2250 lbs.
It performs extremly well and there have been no problems.
My 16'
Captain is listed as 1400 lbs, but when loaded, it is closer to 2000 lbs.
I think the real key is the long wheelbase of the wagon.
I really dont think you should have any problems with a 13' trailer
Brian Hatfield