Tow Capacity Comparisons For 2015 Trucks

So far you haven't proved that calculators that don't include GAWR fail. Since the calculator discussion has been mostly about RV Tow Check, prove to me, and everyone else, the flaws in RV Tow Check with the following data from real tow vehicles that may tow fifth wheel or conventional trailers.

I've ran the numbers and have posted the results above. This calculator has been around for a while and has been on other RV forums. Reviews of its accuracy were about like we see on rv.net. Not much good was said about it.

However your asking for numbers that have nothing to do with what I have said or what the calculator asks for.
These are the numbers straight out of the '15 Ram Body Builders spec sheets PDF for a 2500 Ram 6.4 hemi 5500 FAWR/6000 RAWR the calculator asks for and the same numbers I used in my above reply;

...22800 GCWR..
...10000 GCWR
...6026 gvw

I added
...250 gear/hitch
...340 passenger

calculator says the 2500 Ram can tow a 16184 lb TT or 5th wheel.


Now do the GVWR math or the RAWR math on this truck and same trailer and either way a 16k trailer will overload the GVWR and/or the RAWR/tire capacities of the 2500 truck. Overloading a tire is illegal and dangerous.
This a a example of the fallacy of a calculator. In this case its basing a formula on GCWR calculator that omits the trucks #1 safety numbers (RAWR/tires/wheels/brakes and suspension capacities).

GCWR > or = TV plus TT plus hitch

Then go out actually weigh your TV or TT...how else can anyone ever know where
they are in reference to their ratings?

blt2ski wrote:
There you go! as I have been stating. The reason to go NOT go over the manufactures ratings are, handling, shortens the life of the vehicle, ALONG WITH as I have stated, warranty will and can be denied. THOSE are the reasons for NOT going over the manufactures ratings.
Marty

Thank you, Marty. It's good to know we are now reading the same sheet of music, so to speak. It's tough sometimes trying weed out hearsay and provide actual truth backed up with real data and real published statements. I'm not perfect. I read (study) just as much, or more, as others. Each one of can read the same paragraphs and come away with entirely different interpretations. Does that make one right and the other wrong? I think not. It would be better that some would ask for clarification, rather than making unfounded accusations.

I do get a little bothered sometimes when discussions veer off in a direction that's not really beneficial to the potential RVer. I have to ask, "What would a new RVer go away with after reading this or other threads on RV forums?" And I don't like getting sucked into such non helpful information. That is one reason I don't visit RV.net much anymore.

Dave

JIMNLIN wrote:
Thanks for posting what GM says about not exceeding the front or REAR axle rating as it reinforces my point I've made that the calculator doesn't take in any of the GAWR's into consideration anywhere which leads to over loading the RAWR on "SOME" high GVWR vehicles with low RAWR numbers.

GAWRs are not the primary function within Title 49 in consideration of braking, tire and rim capacity. Most anyplace where it’s written “GAWR,” it refers to the sum of GAWRs should not be less than GVWR. GVWR is the supreme rating regardless of the sum of GAWRs.

Title 49 says hundreds of tech things but nowhere does it say that GVWR is supreme over the GAWRs.
Tire and rim capacity are selected by the vehicles GAWR if you take the time and read 571.110/.120 and has nothing to do with the trucks GVWR.

Brakes.....
NHTSA says this about components of the GAWR:
"Gross Axle Weight Rating is the rated load-carrying capacity of an individual axle and wheel assembly. (It represents the load that may be steadily sustained by the components in the system; i.e., tires, rims, hubs, bearing, axles, brakes, suspension, sub frame, etc. with the GAWR limited by the components with the lowest working rating"

or another source...

RMA (rubber manufacturers)

• GAWR: Gross Axle Weight Rating (for each axle) -
The maximum weight rating that the components
(tires, rims/wheels, brakes, springs, and axle) of
each axle are designed to support. This is
determined by the lowest design capacity of any
component. In other words, if the wheels have the
lowest design capacity of any component on that
axle, installing tires with a higher load capacity
does not increase the GAWR. By regulation, the
tire load rating times the number of tires on that
axle must equal or exceed the GAWR for that axle.

and for a trailer.....
dexter axle;

The Gross Axle Weight Rating (GAWR) of your running gear is determined by the lowest rated component in the assembly. The capacity of the wheel, tire, axle, brake, springs/rubber and hub are all considered.

You have still chosen not give an answer to my last two questions. Additionally, you're putting words in my mouth that I did not say.

So far you haven't proved that calculators that don't include GAWR fail. Since the calculator discussion has been mostly about RV Tow Check, prove to me, and everyone else, the flaws in RV Tow Check with the following data from real tow vehicles that may tow fifth wheel or conventional trailers.

GCWR:
GVWR:
Front GAWR:
Rear GAWR:
Vehicle GVW:
Vehicle VIN:

Here's another example for you: The Ram 3500 DRW pickup with 4.10 gearing can be rated to tow up to 30,000 lbs. The only way to get that same rating in the chassis cab (that is using the same engine and transmission) is to use 4.88 gearing.

Ram knows that guy buying the chassis cab will be working the truck harder than the typical pickup buyer. They had to change the specification rating between the trucks to cover their warranty period.

Oh, I have some GM OM's from the 80's, those even state, If I stay under 25mph, I can up the tow ratings by 25%!

Along with, as Jimlin and I have HAD to deal with legal issues pulling trailers with our rigs. We know, that LEO/CVEO's may or may not in most situations enforce manufactures ratings. There have been 5 or 6 former and current CVEO's that post on here. NONE of them enforce manufactures ratings. They state they are "warranty/performance ratings" only!

Marty

There you go! as I have been stating. The reason to go NOT go over the manufactures ratings are, handling, shortens the life of the vehicle, ALONG WITH as I have stated, warranty will and can be denied. THOSE are the reasons for NOT going over the manufactures ratings.

I can design a trailer that will move a million lbs of cargo on it, it would take special permits etc. Hook up 5 or 6 duramax or equal powered pickups, move the load the 500-1000 miles max the state and Federal DOT would let me and be legal! Yeah said pickups might be toasted at the end. BUT, there is no law(s) that state I can not do this. I can find multitudes of them that state I can. So at the end, I sell the pickups to a junk yard.....oh well, cost of doing business.

As I also stated earlier, the SAE specs use 4 starts forward and backward on a 12% grade as minimum spec. What happens if I am at the supposid rated GCWR on a 30% grade? probably will not move! I do not know the min std is 12%, fry a transmission, I pay for the todays 10K auto tranny replacement. It was $3000 back in 91 when I fried a th400 on a low 20% grade driveway 4K under the gcwr GM gave me for that particular R3500 dually cab and chassis rig I had. Since this time, I have not trusted manufactures ratings to do what I need a rig to do. Hence why when I bought my MDT, I made sure the drive train would go up 30% grades at the wt I would be driving at. up to 30K lbs. I can do this with a 185/335 non turbo 7.3 diesel. My no sold 05 dmax dually, 26% at 20K lbs, my 96 6.5td with a whopping 12500 gcwr, can do 30% at 20K lbs. Neither the 7.3 or 6.5 are as fast as the dmax at any equal weight on a 3-5% freeway grade. BUT< they will get to the job site if the grade is over 25-26%, vs the dmax will stall out on the steeper grades, 3000lbs BELOW it stated gcwr. If I toast the tranny overheating it. I've bought the tranny.

Its more important for folks to know "what is behind" the door of the ratings. Which is generally speaking, hard to find out in light duty trucks. One can find the meanings, how a rig is rated in MDT and HDT trucks. It is very easy to have a truck speced to your needs in the upper ranges. Where as with light duty trucks you get a one size fits all. A problem with the SAE specs. I as a contractor know I will be driving up local roads and driveways that are in these grade percentages. I NEED and WANT to know if a rig will do what I NEED it to do. This is what the ratings need to tell me. How I can also modify them to suit my needs.

I made a dmax engineer squirm at te factory on 9-7-11, ie friday before 9-11. I asked, how steep a grade I could pull in first gear. He said with BIG googly eyes, its a mtn climber! I replied, yeah right. I was told that about my 89! So how steep a grade can I pull? as I have/had a formula to tell me the intitial grade starting of the rig, at the time, it was around 20% at 20K lbs with the mid 500 lbs of torque it had. more than the R3500, still less than my NV4500 trannied 6.5! He did not like what I was saying, had to look at another person there, I gave them an email so they could send me the specs at the office, not in the lunchroom where we were at......NEVER got the actual spec to see if my figures were correct!

My step father was an engineer at Boeing. He was the one that showed me not to always trust an engineer spec or rating. If I the end user did not say what spec I needed, it would probably get designed incorrectly. I've used that motto in 30 some odd years of being a contractor too. If the std spec for the pavers, wall block etc does not seem to be correct, I ask an engineer to verify my gut feeling that it is indeed incorrect, then how do I need to build the project to meet the spec!

As I have said before, I can run legally down the road OVER the manufactures ratings, not get an overweight ticket, IF I have bought/paid enough tax to cover the damage to the road bed I am doing. As long as I do not go over 20K per axel, for most of us with single wheel rigs, this will be 10K per axel as we do not have enough tire width to bridge/spread the load over the road bed! Can an LEO get me off the road at or just below these limits. Oh trust me......I'm screwed if I am at 20K in my C2500, or 32K in my dually pickup! I'll be taken off the road with something wrong! 2-300 lbs over a manufactures gvwr rating......unless the trailer is swaying more than 12-18" side to side, speeding etc, an leo/cveo will not even look at me! The only folks that will look at me will be the RVNET weight police!

Marty

Thanks for posting what GM says about not exceeding the front or REAR axle rating as it reinforces my point I've made that the calculator doesn't take in any of the GAWR's into consideration anywhere which leads to over loading the RAWR on "SOME" high GVWR vehicles with low RAWR numbers.

GAWRs are not the primary function within Title 49 in consideration of braking, tire and rim capacity. Most anyplace where it’s written “GAWR,” it refers to the sum of GAWRs should not be less than GVWR. GVWR is the supreme rating regardless of the sum of GAWRs.

Title 49 says hundreds of tech things but nowhere does it say that GVWR is supreme over the GAWRs.
Tire and rim capacity are selected by the vehicles GAWR if you take the time and read 571.110/.120 and has nothing to do with the trucks GVWR.

Brakes.....
NHTSA says this about components of the GAWR:
"Gross Axle Weight Rating is the rated load-carrying capacity of an individual axle and wheel assembly. (It represents the load that may be steadily sustained by the components in the system; i.e., tires, rims, hubs, bearing, axles, brakes, suspension, sub frame, etc. with the GAWR limited by the components with the lowest working rating"

or another source...

RMA (rubber manufacturers)

• GAWR: Gross Axle Weight Rating (for each axle) -
The maximum weight rating that the components
(tires, rims/wheels, brakes, springs, and axle) of
each axle are designed to support. This is
determined by the lowest design capacity of any
component. In other words, if the wheels have the
lowest design capacity of any component on that
axle, installing tires with a higher load capacity
does not increase the GAWR. By regulation, the
tire load rating times the number of tires on that
axle must equal or exceed the GAWR for that axle.

and for a trailer.....
dexter axle;

The Gross Axle Weight Rating (GAWR) of your running gear is determined by the lowest rated component in the assembly. The capacity of the wheel, tire, axle, brake, springs/rubber and hub are all considered.

blt2ski wrote:

DW-gray wrote:

blt2ski wrote:
Title 49 is what an OEM has to build to. The individual states, do not enforce this spec in licensing or equal. As there is not a way to field test this spec when you are pulled over.So the states whether own field tests that will hold up in court.

One can spout all they want about this or that spec, but from a legal field test or equal issue, it needs to be black,k and white for an Leo to ticket, or get you off the road somehow with a law. Mean while in civil.court, the bar is much lower, so some of these specs will hold up in court.

I know in Washington state, NONE of these specs are used by Leo or cveo folks.

Marty

Don't really understand the reason you want to bring enforcement or other legal issues into this thread. That's not part of the discussion, nor should it be. Title 49 is related to what is required for manufacturers and as such, manufacturers are required place a certification label on the vehicle that includes GVWR, GAWRs, ect. Those are the weights that are never supposed to be exceeded, as well as the GCWR. And when determining towing capacity, GVWR, GCWR and GVW are used.

Its not part of the disCUSSion......wrong! you yourself are saying one needs to stay below the manufactures ratings. From a legal standpoint, that is SOOOOo totally false it is not funny. From a warranty standpoint, YES you need to stay under the ratings. BUT, there is NO LAW that states you need to stay under the manufactures ratings! So from MY standpoint, yes it is recomended you stay under the ratings.........BUT you will not be hauled off to jail for being over those ratings. You will not be fined for JUST being over those ratings, nor will you get any kind of ticket from a law enforcement person for being over said ratings. IT IS LEGAL to be over the ratings!

So when you and others state, I have to be under these ratings like it is a law, legal etc. You have brought the law part of this into this disCUSSion!

The ONLY weight law you have to follow, is the "Federal Bridge Laws" which state you get up to and no more than 20K lbs per axel. An LEO or equal can not stop you, bring you to jail etc for being over this amount. They can get you fined! they can make you move the load so you are under this wt, assuming it is possible to do so....This is also a non following fine, unlike a speeding ticket which can follow you around!

So for all the "sky is falling" baloney you and others are saying about being over weight, is very false!

IF you are truly unsafe in operation, stopping due to field tests etc.....oh, your screwed! but being overweight will not hurt you in the least per say!

Marty

Marty,

I just reread all my comments to reassure myself I didn't say what you are insinuating. Nowhere in this thread have I made any comment that even implies that any legality was involved in the tow ratings or exceeding any of the ratings. The fact is, I have long avoided such issues because, just like you implied, I do not know of any state that writes a citation for being overweight. On the other hand, some states require a weight declaration as part of the registration. That is separate issue.

There are primarily two reasons that every manufacturer and owner’s manual warns drivers to never exceed GVWR, GAWRs and GCWR.

SAFETY and vehicle longevity.

Here is the warning from the 2015 Chevrolet Silverado Owner Manual on page 9-18:

“Do not load the vehicle any heavier than the Gross Vehicle Weight Rating (GVWR), or either the maximum front or rear Gross Axle Weight Rating (GAWR). This can cause systems to break and change the way the vehicle handles. This could cause loss of control and a crash. Overloading can also shorten the life of the vehicle.”

And here is this caution below the warning written above (which I’ve never discussed):

“Overloading the vehicle may cause damage. Repairs would not be covered by the vehicle warranty. Do not overload the vehicle.”

DW-gray wrote:

blt2ski wrote:
Title 49 is what an OEM has to build to. The individual states, do not enforce this spec in licensing or equal. As there is not a way to field test this spec when you are pulled over.So the states whether own field tests that will hold up in court.

One can spout all they want about this or that spec, but from a legal field test or equal issue, it needs to be black,k and white for an Leo to ticket, or get you off the road somehow with a law. Mean while in civil.court, the bar is much lower, so some of these specs will hold up in court.

I know in Washington state, NONE of these specs are used by Leo or cveo folks.

Marty

Don't really understand the reason you want to bring enforcement or other legal issues into this thread. That's not part of the discussion, nor should it be. Title 49 is related to what is required for manufacturers and as such, manufacturers are required place a certification label on the vehicle that includes GVWR, GAWRs, ect. Those are the weights that are never supposed to be exceeded, as well as the GCWR. And when determining towing capacity, GVWR, GCWR and GVW are used.

Its not part of the disCUSSion......wrong! you yourself are saying one needs to stay below the manufactures ratings. From a legal standpoint, that is SOOOOo totally false it is not funny. From a warranty standpoint, YES you need to stay under the ratings. BUT, there is NO LAW that states you need to stay under the manufactures ratings! So from MY standpoint, yes it is recomended you stay under the ratings.........BUT you will not be hauled off to jail for being over those ratings. You will not be fined for JUST being over those ratings, nor will you get any kind of ticket from a law enforcement person for being over said ratings. IT IS LEGAL to be over the ratings!

So when you and others state, I have to be under these ratings like it is a law, legal etc. You have brought the law part of this into this disCUSSion!

The ONLY weight law you have to follow, is the "Federal Bridge Laws" which state you get up to and no more than 20K lbs per axel. An LEO or equal can not stop you, bring you to jail etc for being over this amount. They can get you fined! they can make you move the load so you are under this wt, assuming it is possible to do so....This is also a non following fine, unlike a speeding ticket which can follow you around!

So for all the "sky is falling" baloney you and others are saying about being over weight, is very false!

IF you are truly unsafe in operation, stopping due to field tests etc.....oh, your screwed! but being overweight will not hurt you in the least per say!

Marty