A lot depends on how heavy the tow vehical is, I pull with a diesel F250 so my 12' trailers tongue wieght is of no consequence. However, the worst thing can be if you are too light on the trailer, then the trailer itself is affected and will tend to sway dangerously. Now, when I am towing my 12000 lb travel trailer, I use wieght distrubuting equalilzer bars which also makes a heavy tongue less noticable.

Randy