Hi there, I have a 17' foot Casita
that I tow with a 1/2 ton Suburban. I've towed heavy trailers for 30 years and didn't think I'd need the weight
distribution hitch or sway bars....until I pulled it home in the worst thunderstorm I've ever seen coming back from Wilmington, NC. The wind was so strong and the rain so intense that the Semi trucks got off the road.
There was almost minimal effect on the Casita
. The weight
distribution is also more important than you might think-it keeps your tow vehicle in it's normal posture which greatly improves braking and handling. Both features were invented for good reason. Probably not much of an issue on a 13' but on the bigger ones it's great.