So my wife and I are going to be getting a truck and a fifth wheel soon. We’re using it for full time so it’s going to be a bigger guy for sure. But in my months of research, article reading, and trolling YouTube, I cannot understand what capacity tow rating I need versus the weight I’ll be actually carrying in an RV/fifth wheel. I’m trying to understand these numbers and abbreviations. Things like GVWR, GCWR, dry weight, wet weight, and I’m honestly not understanding the actual figures. Every explanation I’ve found just seems to repeat the same words in a different order and it doesn’t help. Sooooo, explain it like I’m five: what is the tow rating I need and the actual capacity of what a fifth wheel should hold? I swear I’m not an idiot, I just don’t understand.
In: Other
Curt has a great explanation of each term: https://www.curtmfg.com/towing-capacity
If you want to boil down to bare numbers, you need the weight of the driver, passengers, and any cargo going in the truck. That’s the payload. Assume the trailer’s GVWR is going to be the weight you are towing. For towing calculation, ignore the dry weight.
Trailer GVWR + truck curb weight + payload must be less than the truck’s gross combined weight rating.
Trailer GVWR must be less than the truck’s 5th wheel tow limit.
I don’t have numbers. But I’ve been full time rving for about 6 years now. I have a 2013 Ford f250 diesel single rear wheel short bed and a forest river 35′ fifth wheel with two axles. My truck sags when hooked up to the rv with stock suspension. Pulls just fine power wise no problem. Adding air bags to the f250 handles the weight just fine. So really a f350 single or dually would pull any fifth wheel just fine on stock suspension. Plus I used to deliver rvs years ago and I had a f350 dually then. Never had a problem.
Honestly, rvs are made to be towed with pickups so I wouldn’t worry so much about the weight. If you get a 350 or equivalent you’ll be fine.
There are youtube videos that go into this in depth. It’s more complicated than a simple comment can cover.
Dry weight: Vehicle without fluids. Ignore this, you’ll never see the truck in this state.
Wet weight (or curb weight): Vehicle with all fluids and fuel ready for you to get in and drive. So, just like it was presented to you at the dealer.
Gross Vehicle Weight Rating (GVWR): The total weight you can have on your truck’s axles. This includes the truck curb weight, people, cargo (in truck and in bed), and the weight the trailer puts on the tongue (or fifth wheel). So count all your weights in the truck, add the fifth wheel weight, and get a truck that has a GVWR higher than that. The trailer manufacturer will list the fifth wheel weight with nothing in the trailer (this will go up if you put anything in the trailer in front of the axles).
Gross Combined [Vehicle] Weight Rating (GCWR or GCVWR): Combined is the key word here. Weight of truck, passengers, and cargo, and the total weight of the trailer including contents (don’t count the tongue weight twice, just truck, people, cargo, trailer). Same as above, add it up and get a truck that exceeds this number. The trailer manufacturer will list the total trailer weight with nothing in it, you add what you plan to put in the trailer.
Your truck must be good enough to handle both numbers, not just one or the other.
Public service announcement:
Towing can be dangerous if you don’t know what you’re doing, especially with a heavy fifth wheel. Even things like how you distribute cargo in the trailer can be dangerous, such as putting too much extra weight in the back can cause instability that makes you get into a side to side swaying. Read the owner manuals of truck and trailer. The truck maker web site most likely has a comprehensive towing guide for your truck.
Talk to the guy selling the RV. Milk him for all the advice you can if they want a sale. Then do the same at the truck dealer. Remember to order the truck with the highest towing package. Another thing you’ll have to learn is how to adjust the brakes on the trailer. Too little trailer braking and your truck does too much work and stopping distances increase a lot (possibly dangerously, like you hit the brakes and the trailer pushes you through the intersection). Too much trailer braking and you may lock up your trailer brakes as it tries to drag your truck to a stop, which is bad. You can feel when the trailer is pushing you when you brake, so you adjust up a bit.
Or, find an RV club near you and ask, ask, ask.
Also, if you’re doing this a lot as you say you may want to consider a diesel truck, as they’re well-suited to a lot of heavy hauling. You can get away with a much smaller diesel too. For example with the Chevys the 3.0l six cylinder diesel can haul just about as much as the 6.2l gas V8 (both around 19,000 GCWR), and a lot more than the 5.3l gas V8.
Never be afraid to ask a towing question, as your life may depend on the missing knowledge. Ask away, about that or diesels.
Edit: I have no experience towing RVs, but a lot towing trailers.
There are a bunch of terms thrown around ahead, but ask me any questions and I’ll try to clarify.
There are two broad term groups that matter. Weight _ratings_ and actual _weights_. If a weight is listed as GVWR, that is the weight _rating_. That means it’s the maximum total weight that can be placed on that group.
When you actually go to a cat scale, you get a GVW or gross vehicle _weight_ instead. This is current actual weight of the truck or combination, in the _exact_ configuration you have it setup as.
The GCWR or Gross _Combination_ Weight Rating is the _max_ weight of truck and trailer. This is the maximum weight you can safely (and legally) pull, and more importantly, stop again.
The GVWR or Gross _Vehicle_ Weight Rating is the _max_ weight of just the truck, or of _just _ the trailer.
Then you need to find the GAWR or Gross _Axle_ Weight Rating. This is how much weight each axle can carry. All three of these can be found on the door card in your truck and on the front left corner of your trailer.
Lastly, the load rating of your tire. This is what each tire can carry. Multiply by two, because you have two on each axle. The correct load rating should match your GAWR.
If you have a dually, there is a derating factor you need to apply, I believe about 20% ish? Depends on tire. In case one tire in a set blows, the other tire suddenly takes all the weight and needs to be able to do so, that’s why duallies can’t carry double the weight of singles.
To sum this up: Your truck, fw, hitch, and stuff cannot weigh more than your GCWR.
Your truck, when coupled to the trailer and taking the pin weight, cannot weigh more than your GVWR, and likewise for the trailer.
Your front and rear axle cannot exceed their GAWR.
And lastly, ensure you have the correct tires with the correct load range to match your GAWR. OEM tires usually do, but aftermarket may not.
I won’t get into dry and wet weights as they depend on what exactly you’re doing and can vary.
So. GCWR is GVWR of the whole truck _plus_ GVWR of the whole trailer. This is the max truck, trailer, and hitch can weigh.
GVWR is the max either the truck or the trailer can weigh.
GAWR is the max each axle can weigh.
Now for a new term – I already mentioned it, but it’s an important one. Pin weight. Like tongue weight on a bumper pull, it is the weight carried _directly_ by the truck. It’s typically around 20% of the gross trailer _weight_, but can be as high as 25%.
The reason it’s important is because your GAWR on your rear axle must be more than the weight on the back of the truck, the weight of its share of anything in the truck, the weight of the hitch, and the tongue weight of the trailer.
All this can be weighed at a cat scale as follows:
Drive onto the scale, positioning the front axle in the first yellow box, the rear axle in the second yellow box, and the trailer’s axles in the long yellow box. Activate the intercom and tell them a truck number you can remember. Then park the truck, go inside, and pay for the ticket. It’ll have four weights on it.
It might look like this:
STEER AXLE 12000 lb
DRIVE AXLE 34000 lb
TRAILER AXLE 34000 lb
GROSS WEIGHT* 80000 lb
The first two numbers added up need to be less than the GVWR of your truck, in this case 46000 lb.
The first two numbers individually must be less than the GAWR of your front and rear axles.
The third number needs to be less than the GAWR of your trailer.
The last number needs to be less than the GCWR of your truck and trailer.
Now put the trailer down in a spot and take just the truck onto the scale. Do the same thing, but this time it’s a reweigh. Get another yellow ticket.
This one might look like this.
STEER AXLE 10000 lb
DRIVE AXLE 6000 lb
TRAILER AXLE 0 lb
GROSS WEIGHT* 16000 lb
Now, subtract the fourth number from this ticket from the fourth number from the _first_ ticket, where you had the trailer. This gives you the actual weight of the trailer, and it needs to be less than the trailer GVWR.
Latest Answers