sjt wrote:
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How does the actual towing of the trailer differ as you go larger? ...
Actually towing a shorter trailer vs a long trailer is no different. Going forward, you'll not notice any difference.
The difference you'll experience is when you make a turn or attempt to pass a vehicle.
When turning, the trailer tires will track inside the turning radius of your tow vehicle. If you are not watching your rear view mirrors, you can easily turn and the side of the trailer will hit a street sign or a light pole on the corner, or worse, another vehicle when you attempt to turn around it; for example, left hand turns at intersections.
It only takes a couple practice turns, left and right, to figure out how much "swing" you need to give the trailer to make any turn.
The very first thing I do after getting a new trailer of any kind, is to hitch and go to the closest parking lot, turn the steering wheel as sharp as I can until the tow vehicle and trailer are in a complete turn, and hope the side of the trailer tongue does not actually touch the back of the tow vehicle. I then get out of the vehicle and look where the tires are actually tracking different between the tow vehicle and the trailer. If the parking lot is wet and it leave tire tracks, this is a marvelous and eye-opening exercise that is well worth a few minutes doing.
The other thing to watch for, with any trailer is passing another vehicle. After passing the other vehicle, you always have to remember that you have 10, 12, 15, 30, 41 feet of trailer behind you, and you just can't move over as soon as the tow vehicle get's past the passing car or the trailer will slam into them. It takes a little awareness and a lot of watching your mirrors to tell when you have completely cleared the passed vehicle with both the tow vehicle AND trailer. And of course, the longer the trailer, the more distance you need to pass. As long as you are fully aware you have plenty of room, then passing is really a non-issue. But for someone who has never towed before, it's a frightening experience to have the car beside you wildly start honking their horn because the trailer is drifting into their lane and they are RIGHT beside the trailer on either side. You finally catch them in the mirror just to see the the one finger salute as they pass on by.
Another thing, the longer the trailer, the wider the trailer swing is. Again, a test run in an open parking lot is your best friend. The longer the trailer, the longer the distance from the trailer tires pivot point to the end of the trailer. Far to many folks (including myself) have clipped objects with the tail of the trailer when making turns. Clearance, distance, and a bit of parking lot practice, and you will not have any problems at all with a longer trailer. And oh, everything said here is equally as true for a shorter trailer, it's just the distances are shorter.
Hope this helps.
Edit:
I've been towing "bumper pull" trailers all my life. Since I've been married (33 years), we've had 1 pop-up, 3 travel trailers, 2 different utility trailers, and towed utility trailers and pop-up, and travel trailers for friends, family, and foes alike.
We have had our new Fifth Wheel for 4 weeks now. I've never towed a Fifth Wheel before, ever, until we got this one. Every week-end I have gone to a huge open parking lot (actually the casino in Anderson, Indiana) and practiced backing, turning, and parking backwards with the new 5er. I probably will continue taking it there for a couple more weeks on Sunday's so I can continue practicing until I get the backing and backing in an actual campsite down pat! Last Sunday (week 4), all the bells and whistles finally "clicked", both left and right backing. I was able to back into my own driveway first shot after that last time. I'm excited to go out once more and try again, only this time, I want to experiment with angled parking (left and right).
The reason I share this is because, even seasoned folks who have been doing things for a life time STILL need to practice, practice, practice with new equipment until it becomes second nature.
So, whatever you end up with, I encourage you to practice in an open parking lot. This way, you have confidence in your own ability, and confidence in your equipment too.