View Full Version : Need advice on truck (RAM 2500) + rig (Reflection 337RLS) towing capability!

Guzz Head
12-17-2020, 08:54 PM
Hey everyone, new to trailer life so I'm seeking advice.

I have a 2020 Ram 2500 Diesel Crew Cab (4x4) and have my eye on a Grand Design Reflection 337RLS (fifth-wheel) along with a Pullrite (either SuperLite or SuperGlide) hitch w/ the puck configuration combo.

I've been running the numbers to make sure the 2500 can handle this rig and want to run it past the experts (you all) to make sure I'm good.

I was using this link to calculate payload, towing capacity, etc. but am having trouble finding every specific value.


Specs on the 337RLS - https://www.rvusa.com/rv-guide/2020-grand-design-reflection-fifth-wheel-floorplan-337rls-tr42871

From the Ram website using my VIN I was able to determine my
MAX TOWING - 19143.61LBS

Please let me know if this combo will work.

12-18-2020, 08:32 PM
Guzz, your pin weight when you and Momma have it loaded will be about 2800-3000 pounds. You and DW with a little gear in the truck....500 pounds, hitch a hundred or so. you're already 1500 pounds over the capacity of your 3/4 ton. Easy figures. Your pin weight generally will center at 22% of the RV's gross on a 5th wheel. And your diesel ate your cargo capacity. There are hundreds of people towing with your setup, but that doesn't make it right. Sorry. Should have bought the RV first and TV second. A good rule of thumb.

12-21-2020, 09:37 PM
I have a 2020 Ram 3500 CC 4X4 HO diesel SRW w/Aisan trans, with a 3750# payload rating ( and crazy high towing capacity), and would consider that trailer to be just beyond the comfortable limits of my truck. It’s GVW would put the pin weight at better than 2700#, and thus the payload of the truck in the 90 percentile range on my truck, leaving me only 350-450# under max GVW on the truck/TV in real-life “loaded for camping” trim.

Even with my “1-ton” pickup, I have determined that 13,000# is my threshold for safe, comfortable 5th wheel GVW.

Do people tow longer, heavier rigs with similar trucks? Sure they do, but they aren’t looking at all of the specs around payload, GVW and trying to stay within a percentage of limits. Sometimes I envy the guys who can tow way over their rated payload, and not be stressed by it, but I’d rather roll down the highway with comfort, confidence and low blood pressure, knowing that I am not exceeding any metrics or safety margins.

With a 2500 and 2150# payload, I’d be looking at 5th wheels in the 10,000# GVW range (or less).

Guzz Head
12-21-2020, 09:51 PM
Thank you both for your feedback and at this point I have definitely ruled out the 337. I’ve found it’s crazy how RV sales people will not even run numbers and just say “yeah your truck can pull that no problem”. I’ve learned a ton about payload specs over the past week and have been running towing calculations for hours.

I’ve figured a Grand Design 295RL Reflection would be best. It’s funny they market the 150 series as half ton towable capable lol.

This seems to be a solid option given I really want to stick with a fifth wheel.


12-28-2020, 07:53 PM
put airbags under it and heavy duty springs and enjoy your Rving.

Larry drv 7*3
12-28-2020, 09:56 PM
Be sure you are looking at
GCWR (gross combined weight rating) for towing fifth wheel
Specs are different than just towing capacity
Also check load rating of rear tires to determine load capacity with pin weight

12-29-2020, 06:08 PM
[I]put airbags under it and heavy duty springs and enjoy your Rving.

I believe P T Barnum is credited for the saying. It seems to fit here.

Larry drv 7*3
12-29-2020, 09:51 PM
I bought a 20,000 gross DRV and had a 03 7.3 f250 4x4
Sellers used 2500 with airbags but i upped to a f350 dually for this trailer. 250 was fine for 13,400 lb 94 Avion 5er but need weight on more rubber for security cushion. Keep it shiny side up and out of my lane and mirrors risk is yours

12-29-2020, 10:46 PM
put airbags under it and heavy duty springs and enjoy your Rving.

No amount of owner modification will change the factory certified GVWR by one pound. I would not want to be the one who wrote about intentionally overloading a truck that was subsequently involved in a wreck. Can you say self insurance?

12-30-2020, 07:44 AM
So Goober your saying that only The manufacturer can change the payload capacity!

12-30-2020, 09:17 AM
So Goober your saying that only The manufacturer can change the payload capacity!
It must be by the manufacturer or a certified after-market business. Certainly not by some jack-leg adding a bunch of 'Kentucky go-fasters' and then claiming that his GMC 1500 is now a towing beast.

Big tires? Added leaf springs? Overload shocks? Coon tails and light bars? Dark lens over all lights and a goofy looking exhaust pipe up the rear window? Nope, won't fly, sorry.

Larry drv 7*3
12-30-2020, 09:22 AM
Goober is correct, the certified capacity from manufacturer is the vehicles legal specification. IF vehicle is properly modified to engineered specs the functional capacity can be improved but does not change governments legal gwr ever.
To change gwr
That would take engineered certified load test and a state certification process for homebuilt vehicles

terry and jo
01-04-2021, 10:38 AM
Whatever you do, do NOT go by the vehicle manufacturer's "tow rating" for a truck. With any truck in mind (current one or purchasing a new one), get a dealer to look at the data plate at the door of the vehicle to see how it is equipped. (That includes rear axle ration.) That data will let the dealer tell you just what that vehicle's GCVW (Gross Combined Vehicular Weight) is.

With that weight, if you are looking at using your present truck, then load it up with fuel, passengers and pets likely to be along, and any other gear planned on being carried in the truck. Then, go get it weighed to see what your "working" weight is. Add that "working" weight to the RV's GVWR (Gross Vehicular Weight Rating) and see if that total is less than the truck's GCVW. Also, be sure and look at what the pin weight would be on the trailer and add that to your truck's rear axle weight to see whether the trailer would overload the axle.

Lots of cases where folks have been told, "yeah, your truck will pull that." However, other handling characteristics need to be considered. Can your truck stop all that weight in an emergency? I know of a couple that traded up on trucks after blowing through a red light because of weight and wet roads. Fortunately, they didn't have an accident.

fjr vfr
01-05-2021, 10:52 PM
The RV and truck dealers all use fuzzy math to convince the buyer so they can make a sale. What's worst is often the sales person giving you advise is playing expert but doesn't know what they're talking about.
The biggest concern with a 5th wheel is hitch weight. It will be at least 20% of the trailers gross weight. The pin weight listed in the trailers specs is almost always rated on the trailers stripped weight as it leaves the factory floor...not a realistic weight.
Usually (not always) the trailers gross weight is not the issue with a 5th wheel.
If you want a big trailer you should have a 1 ton, but you still need to check the truck's ratings because they are not all the same as you have found out with your 3/4 ton truck. Good Luck

terry and jo
01-06-2021, 11:02 AM
With regards to the weights, there were some folks on the DRV forums that did RV weighing at rallies and such. He kept records of all the weights that he did on the RV's, and for the DRV's he listed the weights of the various models that they had weighed.

In addition, he went on to explain how the trucks fared with regards to weights and to what extent they might have been overweight. He also mentioned about tire under inflation.

% # Description
16% 16/99 have MDT or HDT tow vehicle
51% 50/99 Have DRW tow vehicle
32% 32/99 Have SRW tow vehicle

100% 32/32 SRW over tow vehicle GVWR (as posted on door tag)
60% 30/50 DRW over tow vehicle GVWR (as posted on door tag)

28% 28/99 Over tow vehicle axle (rear) rating (as posted on door tag)
24% 24/99 Over tow vehicle tire capacity rating (as posted on tire)

30% 30/99 Underinflated tires for load (per manufacturer specifications)

40% 40/99 Over trailer GVWR (as posted on manufacturer tag)
21% 21/99 Over trailer tire capacity (per manufacturer specifications)
11% 11/99 Over trailer axle capacity (per manufacturer specifications)

56% 56/99 Underinflated trailer tires per manufacturer specifications

( ) = previous percentage Data collected between 05/2004 & 06/2010

Note that with regards to the DRV's, and yes, they are very heavy trailers, ALL of the trucks with single rear wheeled axles were overweight and 60 percent of the DRW trucks were overweight.

Larry drv 7*3
01-06-2021, 07:26 PM
Terry and jo, i would guess some are not purchasing replacement tires or checking tires on trailer when purchased.
Tires on tow vehicle as well but not sure how they are sooo overloaded.
My dually and DRV trailer, tires and axles are all a good safety factor under load spec.
What i have Issue with is how manufacturers change the standards used to set vehicle weight rating.
A 2002 350 dually is rated 20,000 but a 2020 is rating 35,000, i call BS for Bending Specs due to market demand.
After 16 years with GM truck Engr and Prototype development design spec was 1-1/2 times build rating. Build a 20,000 rated truck you use materials rated at 30,000. If you saw the stress testing procedures to destruction you can trust the design load spec rating.

terry and jo
01-07-2021, 12:07 PM

What I failed to mention with regards to the weights above is that those were "published" in 2010. Stacey (the guy doing the weighing) is no longer doing weighing. As far as that goes, I don't even know if he is still alive.

Also, all the weights that he based everything on was from the data plate on the trailer or truck.


Larry drv 7*3
01-07-2021, 08:59 PM
Thanks Terry and Joe
I appreciate the update and clarification
More info to evaluate provides more width and depth to decisions