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ShinerBock's avatar
ShinerBock
Explorer
Feb 23, 2015

Are 250/2500 trucks limited by their Class?

Hello all, first time poster here. Sorry in advance for the long post, but I would like to get your guys input on what you think about this because it is something I have been wondering for a while. I figured a group of experience towers would be as good a place as any to get a good take on it to see if you guys come to the same conclusion as some friends and I.

Most of you guys know that trucks are rated by DOT by classes depending on their GVWR from class 1 to 8. For those that don't , Class 1 is any vehicle from 0 to 6,000 lbs GVWR which is where most midsize trucks sit. Class 2 is a GVWR of 6,001 to 10,000 lbs, but is a little different than the other classes because it has two sub-classes. Class 2a are vehicles with a GVWR of 6,001 lbs to 8,500 lbs which is where most of your F150 or GM and Ram 1500s sit. Class 2b is 8,501 to 10,000 lbs which is where most of your F250 or GM and Ram 2500s sit. Class 3 is 10,001 to 14,000 lbs which is where most of your F350 or GM and Ram 3500s sit, and so on with the rest of the classes. I know a truck's payload rating is derived by subtracting it's weight from its GVWR.

From what I know on a parts break down, the 2500 has the same frame, brakes, front suspension, tires, front axle, and rear axles as the 3500 SRW trucks so those components should be able to handle anything that a 3500 can. The diesel 2500 also has the same 68RFE transmission as the non HO Cummins 3500 SRW. The one major thing that is different between the two is that the 2500s have progressive rate coil spring suspension and the 3500s have leaf spring suspension. I am not arguing that a 2500 should be rated to do what a 3500 can. I just wanted to point out the same components for you to know what they can handle.

My focus is on the Class 2b where the 250/2500s sit with its max GVWR of 10,000 lbs, and whether 250/2500s are maxed out because of their class or by their actual GAWR and suspension limitations. Case in point would be a Ram 2500 diesel specs versus a Ram 2500 6.4L specs bellow.



The Cummins and the 6.4L have the same rear suspension yet the 6.4L has a much higher payload. Now, before you say "The rest of the parts cannot handle the extra weight of the diesel engine", the diesel 2500 front suspension has a 500 lb higher GAWR and as I stated above that the rest of the parts besides the rear suspension are the same as the 3500 with these specs.



With only the rear suspension being different between the 3500 SRW and 2500, the front suspension and the rest of the truck is able to handle the 11,700 lbs GVWR of the 3500 SRW so that should not be a limiting factor.

Basically, the following is in a Ram 2500 diesel crew cab 4x4

-The front axle is the same as the 3500 SRW that is rated for 11,700 GVWR

-The front suspension is the same as the 3500 SRW that is rated for 11,700 GVWR

-The brakes are the same as the 3500 SRW that is rated for 11,700 GVWR

-The frame is the same as the 3500 SRW that is rated for 11,700 GVWR

-The rear axle is the same as the 3500 SRW that is rated for 11,700 GVWR

-The transmission is the same as the 3500 SRW that is rated to handle 11,700 GVWR

-The rear suspension is the same as the 2500 6.4L that is rated to handle a 3,150 lb payload.


This leads me to ask why the diesel 2500 has almost 1,000 lb less of a payload rating than the 6.4L 2500. They both have the same rear suspension, the rest of the truck can handle more payload than what the diesel 2500 is rated for, and the rear suspension does not hold the engines weight so why lower payload rating?

Our take was that the diesel 2500 is limited to the 10,000 lbs max GVWR of the Class 2b rather than its own ratings. If the diesel 2500 had a higher payload rating then in would increase its GVWR over the max 10,000 lbs of its class and move it to Class 3 which is where the 3500 is, and Ram or any other truck manufacturer either would not want this or could not do this by regulation. This leads me to believe that the Ram diesel 2500 is limited by is class rather than what it actually can handle.

What is your guys take on it? What do you think the limiting factor is? Is the payload of the diesel 250/2500 limited by the max 10,000 lbs max GVWR of the Class 2b that the 250/2500 are in, or the actual weight that it can handle?

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