What model & size Airstream do you have? I'm hoping to get one...just researching right now. They seem to be much lighter than other travel trailers. Also, what is your rear axle ratio, do you have the 3.92? I read where you want to keep a 20% cushion under your maximum tow capacity for a comfortable margin of safety. I also read on this forum that the 3.92 adds 3000 lbs. to your towing capacity; is that in addition to the 11320 that the website indicates? (I'm not taking into consideration the payload and tongue weight of the trailer, which I understand is about 10% of the weight of the trailer.)