2026 Forest River Sandpiper 3800RK Specs
What the numbers mean before you hitch up
The 2026 Forest River Sandpiper 3800RK is a two-axle fifth wheel that measures 44.08 feet long, 8 feet wide and 13.33 feet tall, and those figures shape your trip more than any photo does. Dry weight is 12,849 pounds. GVWR is 15,500 pounds. Subtract one from the other and you have 2,651 pounds to spend on fresh water, firewood, tools, clothes and the rest of it before you're at the trailer's rated ceiling. That's a real number to plan against, not a rounding error.
| Sandpiper 3800RK at a glance | |
|---|---|
| Length | 44.08 ft |
| Dry weight | 12,849 lbs |
| GVWR | 15,500 lbs |
| Hitch weight | 2,405 lbs |
| Slide-outs | None |
| Fresh water | 50 gal |
| Grey water | 100 gal |
| Black water | 50 gal |
Hitch weight is 2,405 pounds dry, and that load doesn't ride on the trailer's axles. It sits in your truck bed, on the rear axle, stacked on top of the hitch hardware, passengers and whatever else you've got back there. So the question isn't what a truck can pull on paper. Pull the payload sticker on your own door jamb, find your rear axle rating, then check the fifth-wheel tow rating in your owner's manual and see whether 2,405 pounds plus hitch plus people still leaves you room. Plenty of trucks that tow 15,500 pounds on a bumper pull run out of payload long before they run out of pulling power with a pin weight like this one. A new fifth wheel this size wants a truck chosen on payload first.
Dry weight is 12,849 pounds and GVWR is 15,500, which gives you 2,651 pounds of capacity for water and cargo.
Hitch weight is 2,405 pounds dry, and every one of those pounds counts against your truck's payload and rear axle, not the trailer's axles.
Height is 13.33 feet, so that's the number you check against canyon routes, older underpasses and your own garage door before you drive home.
Tanks and solar on the 2026 Forest River Sandpiper 3800RK
Fresh water is 50 gallons, grey is 100 gallons and black is 50 gallons. The grey capacity is the one worth noticing. Two to one over fresh means dishes and showers won't be what sends you looking for a dump station; you'll be refilling fresh long before grey fills up. For a weekend at Flaming Gorge or a few nights outside Moab without hookups, that ratio is what actually determines how long you stay.
There's 200 watts of solar on the roof keeping the batteries fed while you're parked out there.
Tank levels and systems run through the control panel, so you can see where fresh and grey stand before you decide whether tomorrow is another day out or a trip to the dump station.
Sleeping and storage
The bedroom is built around a king bed, which is the size most couples actually want after a day of driving and the size that stops the argument about who gets the edge.
Closet space is the part people underestimate on a coach this long, and this floorplan has closet storage. Hanging space, shelving, the kind of storage that lets two people live out of a trailer for a month instead of a weekend.
Outside, the pass-through storage runs across the coach for chairs, hoses, leveling blocks and the bins you'd rather not carry through the living space. Keep an eye on what it does to that 2,651 pounds of payload, since pass-through storage is the easiest place to quietly load several hundred pounds you forget about.
The walk-around
The outdoor kitchen is the feature that changes how you use a campsite. Cooking outside keeps the heat and the smell of bacon out of the coach, and in a Utah summer at a site in American Fork Canyon or down at Sand Hollow, that's where you'll end up making most meals anyway.
The interior kitchen is laid out with the counter and cabinet space you'd expect in a 44-foot coach, with room to actually prep rather than juggle.
The dinette and living area is where the length pays off. There's room to sit, eat and spread out a map without anyone climbing over anyone.
The bathroom includes a shower sized for an adult, not a phone booth with a curtain.
The awning covers the entry side for shade and the occasional afternoon thunderstorm that rolls across the valley in July.
Stabilizer jacks handle the setup once you're parked and unhitched.
On the options side, this Forest River fifth wheel can be ordered or found with the Summit Package, a third air conditioner with a power saver system, a portable vacuum and the Driftwood interior color. Ask us which of those are fitted on the unit you're looking at, because availability varies from coach to coach on the lot.
If you're shopping fifth wheels for sale in Utah and comparing on paper, the three numbers to carry into the comparison are the 2,405-pound pin weight, the 15,500-pound GVWR and the 13.33-foot height. Those decide the truck, the load plan and the route.
The live listing has the full spec sheet for the unit you're considering. Come see us at Motor Sportsland in Millcreek, bring your truck, and we'll back it under the pin and check how the hitch sits before you commit to anything.
Frequently asked questions
What kind of truck do I need to tow this floorplan?
Work from payload rather than tow rating. With a 2,405-pound dry hitch weight and a 15,500-pound GVWR, you need a truck whose door-jamb payload figure covers the pin weight plus passengers, hitch hardware and cargo, and whose rear axle rating and fifth-wheel tow rating both have room left over.
What is the pin box on a fifth wheel?
The pin box is the structure at the front of the trailer that carries the kingpin, and the kingpin is what drops into the hitch mounted in your truck bed. On this floorplan it's carrying 2,405 pounds dry, and that weight transfers straight to the truck.
How much cargo can I load?
Dry weight is 12,849 pounds against a 15,500-pound GVWR, so there's 2,651 pounds of capacity for water, gear and supplies. Filling the 50-gallon fresh tank uses part of that, so weigh your plans accordingly.
Can I camp without hookups?
Yes. There's 200 watts of roof solar, 50 gallons of fresh water, 100 gallons of grey and 50 gallons of black, and that grey capacity is usually what sets the length of the stay.
How long and tall is it?
It's 44.08 feet long, 8 feet wide and 13.33 feet tall, on two axles. Check the height against your storage, your garage and any low clearances on the route you run most.
In stock now:
- 2026 Forest River Sandpiper 3800RK — Spanish Fork
- 2026 Forest River Sandpiper 3800RK — Millcreek, in Salt Lake City
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