A few days ago, I got this question from a reader via email:
Now, of course, my first thought was, “Heck Yeah! I’m Awesome!”
My next thought was, “Wait a minute… These people must not have gotten too far on the internet…”
And my third thought was, “How can I thank them for their shameless flattery?”
But as I thought about their actual question, it occurred to me that it would be pretty easy to get confused about just how much you can tow, particularly with a smaller motorhome like the one they were considering. I’m not surprised that they got different answers from different dealers either. It really can be confusing.
A couple quick disclaimers before I explain how I answered them. First, while I’ve got a fair amount of knowledge of motorhomes, and with Sprinters in particular; I’m not really a “tow” guy. I actually try to avoid towing. Next, and probably more important – I don’t actually work for a motorhome manufacturer. If there is a specific model you have questions on, you will want to verify things with that manufacturer. You can call them up, it’s OK. All the ones I’ve ever dealt with have been very eager to help customers make the right decision.
The real answer to their question depends, like a lot of motorhome related topics, on weight. I thought it would be easiest to explain this by using an actual test case. But since I gutted and rebuilt our own motorhome, it’s not a good example. So I headed down to General RV here in Utah, where I found a representative small motorhome. Here she is, a Siesta Sprinter 24 ST by Thor Motor Coach.
And, for the sake of argument, we’ll assume we want to tow the same Jeep Rubicon that my reader has, at 4720 pounds.
The first thing to know is that the Siesta Sprinter is built on a 2014 Mercedes Benz 3500 cut-away chassis. You can find the specs for this chassis here:
There are three numbers here that we’re interested in. The first is the maximum towing capacity. It’s listed at 7500 pounds. Your first thought here might be “WOO HOO! We’re done!”, but there’s more to the story.
The next number to pay attention to is the Gross Vehicle Weight Rating (GVWR). It’s listed at 11,030 pounds. This number represents the maximum weight that the vehicle itself is allowed to have. So our theoretical Siesta Sprinter can’t go above the 11,030 pounds. The towed vehicle (the Jeep) doesn’t count toward this number, but the tongue weight of the trailer *does* count here. You can actually find this GVWR number on the tire pressure plate inside the driver’s door. You can also find the axle weights there if you are wanting to set your tire pressure properly.
The third number from the Mercedes Benz page to check is the Maximum Available Gross Combined Weight Rating (GCWR). This is 15,250 pounds. So EVERYTHING – the motorhome, the people in it, the towed vehicle, the water in your tanks (fresh, grey and black), the jumper cables and that ratty blanket you left in the Jeep, the burrito you had for lunch. ALL OF IT COMBINED has to weigh less than 15,250 pounds.
The next thing we want to do is have a look at the hitch. Here it is:
Pretty standard. And of course, the most important thing on the hitch is the weight rating plate. In this case, it says we can tow up to 5000 pounds. When a manufacturer tells you that the vehicle can tow 5000 pounds, this is where that comes from – the hitch rating (typically).
So, this alone would bring our 7500 pound towing capacity down to 5000 pounds. But there’s more. Next, we need to find a weight sticker that was put on by the RV manufacturer. On this model, Thor put it inside the passenger door, but on yours, it may be in a cupboard, or inside a closet. You’ve probably seen it – and hopefully you didn’t peel it off and throw it away.
This gives the Occupant and Cargo Carrying Capacity (OCCC) of the motorhome. Now, so I don’t mistype anything, here’s the definition of this, straight from the RV Safety Education Foundation:
OCCC (Occupant and Cargo Carrying Capacity) (for Motorized RVs only): This figure states the maximum allowable weight of all occupants (including the driver), plus the weight of all food, tools, full fresh water tanks, full LP-Gas tanks and personal belongings. The maximum allowable weight of passengers is based on the number of seat belted positions in the motorized RV. The regulation also states that the “tongue weight of towed trailer counts as cargo.”
On this motorhome, that number is 1178 pounds. So now, it’s time for some math. What this OCCC is telling us, is how much weight we have to play with before we tip over 11,030 pounds. We can subtract to find the weight of the empty RV.
11,030 (GVWR) – 1,178 (OCCC) = 9,852 pounds (the weight of the empty RV)
OK. Now, let’s virtually load up our RV, add on the towed vehicle, and see if we’re over weight. We need to check whether or not the weight of the whole enchilada (The RV, PLUS the towed vehicle) is greater than the GCWR, which in this case was 15,250 pounds.
- Weight of Empty RV: 9852
- Weight of Jeep: 4720
- Weight of Driver (me) 190
- Weight of Passenger 120 (If you’re a guy, you should always estimate the weight of your spouse at 120 pounds. It just works out better for everyone.)
- Full load of water 398 (for this RV, the water weight is listed on the OCCC sticker. If you have to add this in yourselves, be sure to INCLUDE the water in the water heater, like Thor did.)
Adding all those up, I get 15,280 pounds. This is greater than the 15,250 GCWR. We’re overweight.
If we were to try to hook this up and tow, we’d be getting ourselves into a dangerous situation. It doesn’t seem like a lot overweight, but remember, we STILL haven’t added in the weight of a full tank of propane (68.2 pounds), any food, any other cargo, any extra passengers or pets, and a contingency in case you have to travel with full black and/or grey tanks (up to another 398 pounds on this model ). If doing the math isn’t your thing, it’s just as easy (and more accurate) to load your RV up just as you would for a trip, and drive down to a local truck scale.
Once you start adding it all up, you see that you can pretty quickly get overweight – and I’m not just talking about towing. When you consider that this Siesta Sprinter has over 62 cubic feet of exterior storage, it wouldn’t be too hard to tip over the 1,178 pounds of cargo carrying capacity just by filling up the basement!
And speaking of that exterior storage, check out this garage-type storage compartment in the back. If I had had my bike with me, I would have tried to fit it in there! I think I need to go back and check this motorhome out in more detail. (The side-opening compartments are a nice touch too – they won’t be banging on your head!)
So, on this vehicle, Thor could, legitimately, advertise a 5000 pound towing capacity. The fine print would say “when driven by a single flyweight, who carries no water”. To their credit, I couldn’t find an advertised towing capacity from Thor. They took the high road, and just published the weights, and let you figure it out for yourself. And now that you’ve read this, hopefully you can!
So, exactly how much can you tow with a smaller motorhome? Only you can say, because only you know exactly how heavy you roll. But with a little simple addition, and a few specifications, you don’t need to be at the mercy of an RV dealer for this critical info.
I’m sure there will be lots of comments and questions on this one, so let’s hear it down in the comments!