by Jason and Amanda » Sun Jun 29, 2008 8:36 pm
As a general rule you shouldn't exceed 75% of your GVWR or 80% of your max tow rating.
But from personal experience, any trailer under 1500 lbs doesn't really need trailer brakes if you tow with a vehicle weighing more than 2500 lbs. If you tow with a vehicle weighing less than 2500 lbs then i have noticed that you should have trailer brakes on any trailer weighing more than 1000 lbs.
Make sense?
All in all the biggest factors are your grades and elevations, and your tow vehicles towing abilities. I would not feel comfortable stopping a 4000 lb trailer with anything other than a full sized truck or SUV. But really anything under 1000 to 1500 lbs isn't much work for any vehicles larger than say 2200 lbs to get stopped respectably.
As for the transmission situation, well I'm a little uneducated but I do know that most cars have "longer" gears than what should be used for towing therefore putting more stress on the tranny, but at the weights that we are talking (pulling a teardrop) I don't see much risk involved. If you have 4 people in your car, that's about 700-900 lbs anyway. (this goes strictly for GVWR for transmission heat and stopping distance)... trailer weight affects many other factors completely differently than overall weight.
Another thing to consider (mostly for those of us with boats) is your control and stability with front wheel drives. I hate recovering a boat at a steep ramp with a front wheel drive, what a touchy situation. Also front wheel drives lose control proportionally to the tongue weight on the rear of the vehicle. Also front wheel drive half shafts or whatever the drive train is called tends to not be built to standards condusive to heavy towing.