Will Your Truck Tow That Camper? What My CAT Scale Ticket Taught Me About Payload

A few years back I ran my truck and camper across a CAT scale to see where I really stood. The door sticker on my truck says the rear axle is rated for 4,300 lb. The ticket said 4,280. The whole truck came in at 7,740 lb against a 7,760 lb GVWR. Twenty pounds to spare on both. That's about one gas station lunch.

By running the numbers, I learned to watch my payload and put any extra junk in the trailer, spread out evenly and near the axles when I can. The truck bed stays light now. Kinda like trying to fit into your stiff winter pants after wearing gym shorts all summer. Ask me how I know.

If you're shopping for a camper, here's what I'd want somebody to tell me first.

Payload runs out before the tow rating does

The tow rating is the big number on the commercial and the one the dealer brings up. For most half tons and SUVs, payload is the number that runs out first.

Payload is how much weight the truck itself can carry, and everything counts: you, your passengers, the kids, the dog, the cooler, whatever's in the bed, the hitch, and the camper's tongue weight pushing down on the ball. It's on the yellow sticker in the driver's door jamb, the one that says "the combined weight of occupants and cargo should never exceed" some number.

Here's how fast it goes. Say your truck has 1,500 lb of payload:

• You and a passenger: 340 lb
• Two kids: 150 lb
• The dog: 60 lb
• Cooler, firewood and the stuff in the bed: 150 lb
• Weight distributing hitch: 85 lb

That's 785 lb before you hook up. A loaded 26 foot travel trailer can easily put 800 or 900 lb on the hitch. Now you're over, and the tow rating still says you've got thousands of pounds to go.

The camper listing doesn't help either. Every ad shows dry weight, and nobody camps dry. Water is 8.34 lb a gallon, and the brochure hitch weight is a dry number too, so it goes up the minute you load the thing.

Where to find your numbers

You only need a handful of numbers, and most of them are stuck to your truck or your camper.

• Truck door jamb: payload, GVWR (the most the loaded truck can weigh) and the front and rear axle ratings (GAWR).
• Owner's manual or the maker's towing guide: tow rating and GCWR (truck and camper together, loaded). These change with the engine, axle ratio and tow package, so look up your exact truck.
• Hitch receiver label: what it's rated for, with and without weight distribution.
• Camper sticker by the door: dry weight (UVW), cargo capacity (CCC) and GVWR.

The picture up top is my actual door sticker, camper sticker and CAT ticket with the numbers circled. I blurred the VINs and the truck stop address.

Where to put the junk

Anything in the truck counts against payload pound for pound. Stuff in the camper mostly rides on the camper's own axles, as long as you keep it near the axles and spread out side to side. The camper has its own limit too (the CCC on that sticker), so don't go nuts.

Keep an eye on tongue weight while you're at it. Around 10 to 15 percent of the camper's weight is the usual target for a travel trailer. Too light on the tongue and the trailer can start to sway.

Using a CAT scale the first time

Pulling onto a truck scale the first time is a little unnerving. You pull up next to the semis, push a button, and somebody yells at you through a scratchy speaker you can't understand. Here's what they're asking:

• Line up with the front axle on the first platform, the rear axle on the second and the camper's axles on the third.
• Push the button on the speaker box. "First weigh or reweigh?" Say first weigh, unless you were on that same scale in the last 24 hours.
• "Company?" Just say your last name, or RV.
• "Truck number?" Say 1.
• "Trailer?" Say RV.
• When they say you're good, pull off, park, and go inside to pay and grab your ticket.

If you'd rather skip the speaker, the CAT Weigh My Truck app lets you do the whole thing from your phone and emails you the ticket.

If you want the full picture, weigh it three ways: hooked up with the spring bars on, hooked up with the bars off, and the truck by itself. The reweighs are cheap if you do them within 24 hours at the same scale. Those three tickets give you your real tongue weight and tell you whether your weight distribution hitch is set up right.

Running your own numbers

For a quick check on one camper, there's a free RV towing calculator right here on the site. Plug in your door sticker numbers and it shows how close you are.

If you're shopping and have a few campers in mind, I built a spreadsheet for that called Will It Tow? You type your truck's numbers in once, then up to 5 campers. It loads each one the way you'd actually camp and tells you which ones tow and what runs out first. It also prints a dealer sheet with 9 questions to take to the lot, and after you buy, it turns your CAT tickets into real tongue weight, axle loads and payload left. Those photos are in there too, so you know which number is which.

Whichever way you do it, your door sticker, your owner's manual and a scale ticket are what count. I'm just a guy in Kansas City who tows a camper, so double check your own truck's manual too.