Originally Posted by AloraDanin
What are the most important points we should look for?
1 Ton, 4:10 axle ratio, diesel, dually, 2500/3500, and anything else you think we need.
Don't worry about nit noid stuff such as axle ratio. Rely on the GVWR of the trailer and the GCWR and GVWR of the truck. The GCWR of the truck considers the axle ratio as part of the computation the engineers make to determihne the weight capacities of the truck. So rely on the GCWR, not one of the factors that make up the GCWR.
The truck's GVWR limits how much weight you can haul on the truck axles, including hitch weight. GCWR limits how much you can pull with that tow vehicle. You never want to exceed either the GVWR or the GCWR of your tow vehicle.
The trucks GCWR is the max combined weight of the truck and trailer that your well-maintained truck can handle in severe conditions, such as climbing a mountain pass while towing a heavy trailer, without overheating or breaking anything in the drivetrain. When towing right up against the GCWR slimits, you may not be the fastest rig up the pass, but you should make it without overheating or breaking anything. If you exceed the GCWR, then don't count on having a trouble-free trip.
It's good that you have neither the trailer nor the truck yet. You can decide on your trailer, then buy a truck that will tow it without being overloaded.
Step 1. Determine exactly which trailer you will buy. Get the GVWR of that trailer. (Shipping weight plus carrying capacity if GVWR is not listed). Ignore trailer specs of dry weight and dry hitch weight. Use the trailer's GVWR as the approximate wet and loaded trailer weight. Estimate the wet and loaded hitch weight as 20 percent of the trailer's GVWR.
Step 2. Use the wet and loaded trailer weight and hitch weight from above to determine how much truck you need to tow it without being overloaded.
Ignore the truck manufacturer's tow ratings. They all publish extremely misleading tow ratings, using the shipping weight instead of the real weight of the truck, and ignoring the GVWR of the truck as a limiter.
Example: A very popular 5er is the Keystone Montana 3400RL. GVWR is 15,640.
Keystone Montana | Specs
Estimated wet and loaded hitch weight for that trailer will be about 3128 pounds.
So you need a tow vehicle with enough GCWR to tow a 16,000 pound trailer that has over 3,000 pounds hitch weight with a 9,000 pound truck without being overloaded over either the GVWR or GCWR of the tow vehicle.
Results of previous discussions proves that any trailer with a GVWR over about 12,000 pounds requires as a minimum a "one ton dually" pickup to tow it without being overloaded. But even some dually pickups won't be enough, so you have to dig deeper into the GCWR and GVWR of the pickup. For example, a '99-'04 Ford F-350 DRW diesel will be overloaded with that 15,000+ pound trailer.
Colour me confused...It's getting difficult to find such a specific vehicle as we want to buy used.
Using Ford as the tow vehicle example, and assuming you can afford at least a 2005 model with diesel engine, then here's the capacity of a 2005-2010 F-350 DRW (dual rear wheels) with the diesel engine and normal 4.10 limited slip or 3.73 open rear axle. GCWR 23,500, GVWR 13,000.
Subtract 15,640 trailer weight from 23,500 GCWR and that leaves 7,860 max pickup weight before you tie onto the trailer. But any 2005-2010 F-350 dually is probably going to weigh more than 8,000 pounds when wet and loaded for the road, so you'd probably be overloaded with that trailer.
(My '99.5 F-250 CrewCab 4x2 diesel weighed 8,000 pounds with only Darling Wife and me and two puppydogs in it, along with normal tools and options. Add about 400 pounds for a dually, another 400 pounds for a 4x4, and another 200 pounds for a 2005-up. So where my tow vehicle was 8,000 pounds, your '05-up dually 4x4 will probably be closer to 9,000.)
Late in the 2005 model year, Ford added an option called the TowBoss pkg to the F-350 DRW order guide. With the TowBoss pkg, the GCWR increased to 26,000 pounds. But only a small percentage of duallies were made with the TowBoss pkg, so they may be hard to find on the used pickup market. But if you can find a 2005 thru 2010 diesel dually with the TowBoss pkg, then that will probably be enough GCWR for that Montana 3400 5er.
If you can't find an F-350 dually with the TowBoss pkg, then a 2008-up F-450 pickup will be on your wish list. If those are too new and expensive, then look for a '99-up F-450 chassis cab with a diesel engine and hauler bed. Standard on the diesel F-450 chassis cab was GCWR of 26,000, and more was available with factory options. Ford sold a bunch of them, but they are still rare compared to the F-350 DRW pickups.
If you find a 2005-up F-350 DRW with the TowBoss pkg, next check is the GVWR. Ford didn't offer any options to increase the GVWR so it stays at 13,000 pounds with the TowBoss pkg. The hitch weight of that wet and loaded Montana is about 3,128 pounds, so subtract that from the 13,000 GVWR and that leaves 9,872 as the max weight of your wet and loaded dually without being overloaded. Some folks load their F-350 DRW tow vehicle to more than 9,872 pounds before they tie onto the trailer, but not a high percentage of RVers.
So if the Montana 3400 is your trailer and Ford is your brand, then you need a 2005-up F-350 DRW with the TowBoss pkg as your tow vehicle. GM and RAM make similar tow vehicles, but you have to pay attention to the GCWR, GVWR and actual weight of the wet and loaded trucks to decide if it is enough truck for your trailer. Do not assume that any 3500 dually will be enough truck for your trailer.