Purchased a trailer tongue weight scale from Canadian company Princess Auto. Finally got the opportunity to try it out and here are the results. Fun finder 2009 18FBS with full water tank, two full 20 lb propane tanks, two 6 volt batteries, weighed in at 300 kgs or 661 lbs! Now my specification sheets for the 18 FBS says 311 lbs tongue weight, the husky towing weight calculator showed 400 lbs tongue weight with all my stuff weighed. A CAT scale weight of trailer showed 3860 lbs fully loaded. Based on the CAT scale calculation my tongue weight is just over 17% ( 10% would be 386 lbs) and I don’t even have everything I need to go camping in it! The only upgrade we made in the front was remove the thin foam mattress on bed and put in one of those mattress that come in a box. What’s ironic about the 18 FBS it’s got this huge, enter from both sides, front cargo storage area that families would normally fill up with lawn chairs, BBQ, etc., etc. I do use a weight distribution hitch.