This topic comes up frequently on most RV-related sites, so it probably makes sense to discuss it once in a while. I'm a retired teacher/librarian, so research is my thing. I also happen to lean towards engineering, and like math, so numbers play a big part for me.
Some ancient trailer history. Many years ago Wally Byam (of Airstream fame) showed how light his trailers were by towing one with a bicycle. I don't remember how far he towed it, and I'm sure it wasn't very fast, but he did it. Does that mean that bicycles make good tow vehicles for Airstreams? Absolutely not. Fast forward a few years, and Oldsmobile brought out the Toronado, the first modern front wheel drive car. To advertise that fact, they hooked up an Airstream with a weight-distributing hitch and removed the rear tires from the car. They then drove the car for the cameras to prove that front wheel drive works. Does that mean that if you have a front wheel drive tow vehicle you can take the rear tires off (thus saving the wear on them)? Absolutely not. In both cases it was done to prove a point, NOT to show best practice.
How does this relate to weights? Put the proper hitch on the truck and any truck can drag any trailer down the road. Does that mean that any truck can tow any trailer? Absolutely not. Wally Byam pulled that Airstream on level ground. All he had to do to stop was stop peddling, and friction would stop the tow. He wouldn't have tried it on any sort of grade, either up or down. Oldsmobile shot their commercial on a test track with no other traffic around, and at low speeds. They weren't concerned about stopping distance or emergency maneuvers.
When we hook up our recreational vehicles and venture out on the public roads we expect that other drivers will be paying attention to what they are doing and we do likewise. That means that truck and trailer must be capable of changing lanes quickly without overturning and stopping quickly in an emergency. This means that truck and trailer must be matched. An HDT may not appropriate for a trailer that has a gross weight of 3500 pounds. It may well be appropriate for one that has a gross weight of 25,000 pounds.
Because of a change in our needs, we're selling our motorhome and going to a travel trailer. We're looking at 34' Airstreams from the early 2000's. These have a gross weight of around 10,000 pounds and a tongue weight of 1000 pounds. A 2017 F150 might be able to handle this, but it would be pretty close to the limits (and we can't afford one anyway). An F250 of the proper age (2011-2014) can handle it. We're looking at both an F250 and an F350. Why? Going from the MH to the Airstream means that all of the stuff in the basement will have to live in the bed of the truck. Add a topper for the bed and we'll be nearing the rear axle weight limit with the trailer attached, although we will still be below it for an F250. An F350 adds additional weight capacity where it is needed.
My point in sharing our situation is that what works for one doesn't necessarily work for others. The tow vehicle needs to carry not only the weight of the trailer's hitch or tongue weight but also the people, pets, and stuff that rides in or on the truck. That weight can add up quickly.
Earlier I said "an HDT may not be appropriate for a trailer that has a gross weight of 3500 pounds." Such a light trailer can be safely towed by many vehicles. A Smart Car isn't one of them. If you want to drive an HDT truck with a Smart on the back and tow a 3500 trailer you certainly can. If your plan is to upgrade that little trailer to a 5'er that weighs 25,000 pounds next year, it would make sense. People will still look at you funny as you come into the campground, but you will have opportunity to introduce yourselves and talk about your plans.
When we started talking about selling our Foretravel and getting a towable we talked about 5'ers. The ones we liked the best were heavy, though, needing at least an F450 to safely handle their weight. That 25,000 pound gross weight I mentioned earlier came from one of those that we looked at. That means that somewhere between 5000 and 6000 pounds will be dropped on the rear axle when we hook up. That doesn't include the weight of the hitch that rides in the truck bed permanently.
Back when he wrote his famous book, Trailer Travel Here and Abroad, Wally Byam said that the weight of the trailer should always be less than the weight of the tow vehicle. Both trailer brakes and tow vehicle brakes have greatly improved since he wrote that, but it is still a good idea to have the two weights match fairly closely.
This topic comes up frequently on most RV-related sites, so it probably makes sense to discuss it once in a while. I'm a retired teacher/librarian, so research is my thing. I also happen to lean towards engineering, and like math, so numbers play a big part for me.
Some ancient trailer history. Many years ago Wally Byam (of Airstream fame) showed how light his trailers were by towing one with a bicycle. I don't remember how far he towed it, and I'm sure it wasn't very fast, but he did it. Does that mean that bicycles make good tow vehicles for Airstreams? Absolutely not. Fast forward a few years, and Oldsmobile brought out the Toronado, the first modern front wheel drive car. To advertise that fact, they hooked up an Airstream with a weight-distributing hitch and removed the rear tires from the car. They then drove the car for the cameras to prove that front wheel drive works. Does that mean that if you have a front wheel drive tow vehicle you can take the rear tires off (thus saving the wear on them)? Absolutely not. In both cases it was done to prove a point, NOT to show best practice.
How does this relate to weights? Put the proper hitch on the truck and any truck can drag any trailer down the road. Does that mean that any truck can tow any trailer? Absolutely not. Wally Byam pulled that Airstream on level ground. All he had to do to stop was stop peddling, and friction would stop the tow. He wouldn't have tried it on any sort of grade, either up or down. Oldsmobile shot their commercial on a test track with no other traffic around, and at low speeds. They weren't concerned about stopping distance or emergency maneuvers.
When we hook up our recreational vehicles and venture out on the public roads we expect that other drivers will be paying attention to what they are doing and we do likewise. That means that truck and trailer must be capable of changing lanes quickly without overturning and stopping quickly in an emergency. This means that truck and trailer must be matched. An HDT may not appropriate for a trailer that has a gross weight of 3500 pounds. It may well be appropriate for one that has a gross weight of 25,000 pounds.
Because of a change in our needs, we're selling our motorhome and going to a travel trailer. We're looking at 34' Airstreams from the early 2000's. These have a gross weight of around 10,000 pounds and a tongue weight of 1000 pounds. A 2017 F150 might be able to handle this, but it would be pretty close to the limits (and we can't afford one anyway). An F250 of the proper age (2011-2014) can handle it. We're looking at both an F250 and an F350. Why? Going from the MH to the Airstream means that all of the stuff in the basement will have to live in the bed of the truck. Add a topper for the bed and we'll be nearing the rear axle weight limit with the trailer attached, although we will still be below it for an F250. An F350 adds additional weight capacity where it is needed.
My point in sharing our situation is that what works for one doesn't necessarily work for others. The tow vehicle needs to carry not only the weight of the trailer's hitch or tongue weight but also the people, pets, and stuff that rides in or on the truck. That weight can add up quickly.
Earlier I said "an HDT may not be appropriate for a trailer that has a gross weight of 3500 pounds." Such a light trailer can be safely towed by many vehicles. A Smart Car isn't one of them. If you want to drive an HDT truck with a Smart on the back and tow a 3500 trailer you certainly can. If your plan is to upgrade that little trailer to a 5'er that weighs 25,000 pounds next year, it would make sense. People will still look at you funny as you come into the campground, but you will have opportunity to introduce yourselves and talk about your plans.
When we started talking about selling our Foretravel and getting a towable we talked about 5'ers. The ones we liked the best were heavy, though, needing at least an F450 to safely handle their weight. That 25,000 pound gross weight I mentioned earlier came from one of those that we looked at. That means that somewhere between 5000 and 6000 pounds will be dropped on the rear axle when we hook up. That doesn't include the weight of the hitch that rides in the truck bed permanently.
Back when he wrote his famous book, Trailer Travel Here and Abroad, Wally Byam said that the weight of the trailer should always be less than the weight of the tow vehicle. Both trailer brakes and tow vehicle brakes have greatly improved since he wrote that, but it is still a good idea to have the two weights match fairly closely.