How important is a dually?

[KHB]

My wife and I are preparing mentally for the move to fulltiming and have been convinced by our research that Excel will be our future choice. Probably a 33ft 5th wheel.
I am wondering how important is it to have a dually? Or to have a pickup beyond the 1/2 ton range? Any ideas?

[RustyJC]

Seeing that this is your first post, welcome to iRV2. We're glad to have you aboard.

Before I start, I've linked your post to the Excel Owner's forum below so you can get some responses from the Excel owners.

Let me start by saying that a 1/2 ton pickup is a non-starter for any "full-timer" 5th wheel such as an Excel. These are heavy beasts that are far beyond the capabilities and ratings of any 1/2 ton truck. So, let's get on to how to select a truck for 5th wheel towing applications. The following process assumes that you wish to stay within the ratings of the truck manufacturer. If you don't, then your selection criteria is up to you.

First, the dry or empty weights in an RV brochure are pretty useless unless you plan on pulling an empty and unoptioned RV. The more conservative and realistic approach is to base your calculations off the 5th wheel's GVWR, or gross vehicle weight rating. This is the rated maximum weight of a 5th wheel with all options and all of your gear as well as any contents of fresh water and holding tanks, propane tanks, etc. As you look at trucks, you'll need to obtain the truck's GVWR (usually located on the door jamb of the driver's door) and GCWR (gross combined weight rating - the maximum allowable weight of a loaded truck plus whatever it is towing - this is usually found in the owner's manual and may vary according to axle ratio.) You will also need some idea of what the truck's LCW (laden curb weight) will be - this is the weight of the truck with all accessories, passengers, full fuel tank, pets, cargo, 5th wheel hitch, etc. just the way you'll be hitting the road. This is significantly higher than the truck's published curb weight which is the weight of an unoptioned base truck with only a 150 lb. driver.

With this data, the calculations are quite simple.

Maximum allowable loaded trailer weight = Truck's GCWR - Truck's LCW

Maximum allowable loaded trailer pin/hitch weight = Truck's GVWR - Truck's LCW

A loaded 5th wheel can carry 20% or more of its total weight as pin/hitch weight which is transferred to the truck. So, for illustration, let's size a truck for a 15,000 lb GVWR 5th wheel. For the purpose of this calculation, let's look at two trucks - the first is a 3/4 ton truck with a 23,000 lb GCWR and a 9,200 lb GVWR and an LCW of 7,500 lbs. The second is a 1-ton dually with a 23,000 lb GCWR and a 11,500 lb GVWR and (due to its heavier components, extra wheels and tires, etc.) an LCW of 7,800 lbs.

3/4 ton truck:

Maximum loaded trailer weight = 23,000 lbs (GCWR) - 7,500 lbs (LCW) = 15,500 lbs.

Maximum loaded trailer pin/hitch weight = 9,200 lbs (GVWR) - 7,500 lbs (LCW) = 1,700 lbs.

With a 15,000 lb GVWR trailer, we're OK on total trailer weight (15,500 capacity versus 15,000 actual). Using 20% of the trailer's GVWR for pin/hitch weight, 0.20 x 15,000 = 3,000 lbs., or 1,300 lbs OVER the capacity of the 3/4 ton truck (1,700 capacity versus 3,000 actual). This is the problem with just about any single rear wheel (SRW) truck - they run out of GVWR (how much they can CARRY) before they run out of GCWR (how much they can PULL).

Now, let's repeat the calculations for the 1 ton dually:

1 ton truck:

Maximum loaded trailer weight = 23,000 lbs (GCWR) - 7,800 lbs (LCW) = 15,200 lbs.

Maximum loaded trailer pin/hitch weight = 11,500 lbs (GVWR) - 7,800 lbs (LCW) = 3,700 lbs.

Using the same 15,000 lb GVWR trailer, we're OK on total trailer weight (15,200 capacity versus 15,000 actual) and OK on pin/hitch weight (3,700 capacity versus 3,000 actual).

There are a number of calculation spreadsheets that go into more detail and allow you to enter actual data - my favorite can be found in iRV2.com member Ken Lenger's signature links. As I have time, I'll provide that link later in the thread unless someone beats me to it.

Hope this helps, and welcome again to iRV2.com.

[Endeavor2BnC]

Our choice of a 1 ton 4x4 DRW waas based on the following:
1. DW wanted the "peace of mind" when driving that if a rear wheel blew she'd still have three to ride on to the safety of the road's shoulder.
2. 1 ton or greater was the only choice. Better to have reserve carrying capacity than be short.
3. We chose Crew Cab w Long Bed. We just wanted room for grandchildren, mom and whom ever else might join us. The long bed allows for bed cover, tool box, 20K Reese Hitch, Extra Small propane bottle & whatever else might happen to need transporting. The locking cover is great for keeping the hitch under cover and anything else that needs private storage except when towing.

All this gives a little extra weight but I still get 11+ mpg towing and 17+ open. The grandkids love the DVD and mom likes the extra room and easier access to the back seat. I wouldn't trade it & DW loves the heated seats.

[RustyJC]

Here's the link to Ken Lenger's towing weight calculation page that I promised - LINK.

Rusty

[LindaH]

We have the Excel in my signature...it's 32' in length.

When we had it weighed in 2007 at the Escapees Spring Escapade (with a full tank of fresh water), our pin weight was 3,475...far too much for even a single rear wheel one ton to handle.

If you're looking at one of the 33xxx models (which are 35' in length), do yourself a favor and get *at least* a 1-ton pickup with duallies. Frankly, if we had decided on one of the larger Excels, we would have bought at least an F-450 or an F-550 (or a Chevy or Dodge equivalent), if not an actual MDT (or even an HDT).

[KHB]

Thanks for this very clear and comprehensive treatment! I am humbled to be the beneficiary of such a full response. It helps sooo much for me to know how to avoid getting a mismatch between the RV and the tow-vehicle. Thanks!

[TXiceman]

Howdy and welcome to iRV2.

Rusty pretty much summed it up for what I would say.

To add to this, forget most of everything the dealer or salesman tells you (RV or truck). Very few of them actually understand the mechanics involved when towing an RV. They may at best throw empty and brochure weights at you. The best thing to do is to spend some time on Ken Lenger's site and learn all of the terms and how to make the calculations yourself.

The salesman is not there to be your best friend and educate you on trailer buying. His job is to get you off the lot with the largest trailer possible and get as much of your money as he can.

For selecting a trailer, you need to look and spend an hour or two in the trailer. You may have to tell the salesman to get lost for a while so that you can look.

Stand in the shower, sit on the toilet and make sure you fit. Does the bath and bedroom have adequate drawers for lines, underwire and such? Make sure the wife is happy with the bath as to her needs for makeup and such.

Next, the kitchen needs to have room for food, pot, pans, silverware and counter space for cooking. Go through the motions of preparing a meal.

Now, do you have room to store a computer, games, and clothing for more than one season, fishing gear, golf clubs, lawn chairs, BBQ grill and the list goes on.

Quiet frankly, a full time trailer will be 35' plus for most folks and this will be pushing the limits of most 1 ton duallies (F-35, 3500 series trucks). The preferred way to approach this is to decide on the trailer that suites your needs, then look for the truck to pull it safely. Do not limit your selection by getting the horse first.

I hope you have a good time looking.

Ken

[KHB]

Linda referred to something that seems important, but I don't know the abbreviations. It was "if not an actual MDT (or even an HDT)". Can someone help?
And a follow-on question: Is four-wheel drive not relevant to pulling an RV safely on pavement?

[RustyJC]

MDT = medium duty truck, also known as a "business class" truck.
HDT = heavy duty truck, typically a modified Class 8 over-the-road tractor.

Four wheel drive is one of the most debated subjects for tow vehicles, but it's really pretty simple. If you plan to travel where you may encounter low traction conditions, then by all means go with the 4x4. Conversely, if you don't need it, then there are a lot of maintenance, fuel economy, handling, ride, towability, cost, etc. benefits to a 2 wheel drive dually.

A lot of northern and off-road users prefer the 4x4s, while a lot of us southerners use 2x4 tow vehicles very satisfactorily.

Rusty

[rockintom]

All the other posters did a great job....I'll only can add my .02 in. I've towed a 35ft Excel of a friend that does just weekend warrior stuff, with his SRW truck and of course we have a 35ft Excel and tow with a dually FT (73,000 miles on Tug). The duals make it so much more stable there is no comparison. I would not consider a SRW truck. Just my IMHO. rockin'

[Jeff_in_The_Dalles]

These guys did an excellent job of explaining things...

In a Single Rear Wheel truck, the gross axle weight rating for the rear axle, and the gross vehicle weight rating, will be the ratings that a 5th wheel will exceed first.

I had a Ram 3500 SRW, which worked fine for my 30' toyhauler. Maybe about 2000 pounds of hitch weight, plus the hitch, and the other stuff that ends up in the bed...

When I got to looking at 40' units, I got a 3500 Dually first. Though the SRW truck towed the 30' unit safely, the dually did it better and was much more relaxing to drive on narrow, windy mtn highways.

When I got the 40' one, I weighed it. Completely empty it would have overloaded the SRW's gross vehicle weight rating, rear axle gross weight rating, and most importantly- it would have exceeded the maximum capacity of the truck's rear tires.

Reasonable minds can differ in whether being a bit over combined weight rating is unsafe, but when you talk about exceeding the rating of the tires...

For me, as long as I have a 5th wheel, I don't think I'll ever own another single rear wheel pickup.


Good luck in your venture into full timing, and I hope you have a good and safe experience.

[LarryGodby]

Quote:

Originally posted by KHB: Linda referred to something that seems important, but I don't know the abbreviations. It was "if not an actual MDT (or even an HDT)". Can someone help?

Here is a link with picture of an MDT.
So What's A Really Good Medium Duty Two Vehicle

MakinSmoke aka Virgil has a Volvo 610 HDT look up a post by him and you will see the rig

[motojavaphil]

When we had the Excel and other 5r's, weight was always a concern. The GVWR of our 35 MKO was 17500lbs as I recall. I towed it with a Dodge dually Long bed, 4X4. Ended up with a Ford F450 which had greater GVWR. The stability factor really shined with the dually. We looked at the MDT's and liked them but felt they were more money than we wanted to spend. The F450 was a great, more affordable alternative. I really was drawn to the Kenworth T2000 HDT. DW was not so taken so it did not happen. Used HDT's are more affordable and are a completely different world. I'd suggest checking them out if only out of curiosity. I like to offroad and found 4X4 dually's are not the tool of choice. I doubt that when and if I ever go back to Excel I'd get another 4X4 unless it was too great a deal to pass on. I think choosing an Excel is a great choice and I wish you the best in your quest.
Phil

[KHB]

Thanks, all, for your depth of interest and knowledge. I trust there are a lot of guests who are or will be benefiting besides myself. I have come a long way from where I started. (The dually word wasn't in my vocabulary until a few days ago! And then I thought the issue behind getting it was traction rather than the bearing of weight. Silly me!
Really, the information you have pointed me to should be a huge help. The need for safety-consciousness is greater than ever. I especially liked that feature of Excel, that they have a big cargo capacity in their RV's.