Hey gang,

Been going crazy with research (as I always seem to do... darn internet). You can see the truck I have, but what you don't know is... it's technically overkill for what I tow. But that's just the way I like it.

So my dilemma has been over the load rating on my up and coming replacement tires. Whenever I say I am going to go with a "D" rated tire, I hear a lot of people give me heat about it being a safety issue to run such a tire when OEM was E rated. Mostly because the truck is so heavy already, that it wouldn't take much to put it over the recommended load of the tire. After thinking about this more and looking at the load carrying capacities of the tires, I realized something. So I thought I would post it up as informative and also open to criticism to try and clear things up for people in the same boat.

The 2500 (and probably the 3500) factory towing packages come as class IV hitches. I have seen most of class IV's in the 7500 - 8500lb range, but Dodge quotes 8500 on their page. Yes, they do say the truck can go 12,500, but it also says properly equipped. I am assuming since class IV will not go that high, they must mean a different hitch or bed hitch for a fiver.

Anyway, if that is the case, then those of us with the factory class IV have a maximum towing capacity of 8500lbs. Proper tongue weight distribution is 10%, so that would 850lbs. Let's round it up to 1000lbs for safety standards to cover ******** like me who just hook and drive. That leaves 500lbs per tire, right?

That said, the Mega cab is ~8000lbs. Assuming weight distribution is equal across all the tires (which it's not), that's 2000lbs per tire for the truck. Add in the other 500lb max for the hitch and that would put you at 2500lb tire capacity.... right? Or did I screw that up somewhere?

Soooo... I have been looking at the Toyo's in a 285 size. Load range "D" in that size goes to 3195lbs... almost 700lbs more than what I calculated above. Considering the heaviest thing I got only approaches 5000lbs.... and assuming that someday I will be presented with the opportunity to tow something heavier.... this tire should more than cover the safety recommendations of what I could put on the hitch. Is this correct? If so, would it be safe to say that those of us using the factory hitches can easily run a "D" rated tire?

Like I said, open to criticism so that I can clear this up and buy the right tire.

DISCLAIMER: I know different tires have different load capacities for different sizes, so you always have to check when buying "D".

 

I just thought of something as I hit post. Since you are using the factory hitch, there would be the possibility of having equipment/material/whatever in the bed. That being the case, it might still be possible to overload the tires in my example above if I had 1400lb of stuff in the bed while hauling 8500lbs or more... would it not? Not likely to happen, but what is the max load capacity of the truck in the bed... and does that count the weight of the tongue on the hitch?

 

IIRC the sidewall of a D rated tire is not a strong as the E rated one an it will flex more to do to the softer sidewall. Also of your towing and get in a wreck they will look at what tires you have on your truck to see if they are the proper E rated tire for your truck and if they are not it will not be good for you.

 

I think that is understood... just makes sense with 8 ply vs. 10 ply. But how does that change whether or not I can safely use it?

To be honest, I am going after the 8 ply to improve the ride quality a little. I don't use it as a 2500 truck, but I won't get into the lengthy reason why (has a lot to do with bed length)... just trying to improve the ride.

 

This last Sat. I pulled 23-24K lbs with my Dodge (4950 on the rear axle 21950 on the GN axles) on D-rated tires w/no probs. They were inflated to their max of 65psi cold. I would have rather done it on E's, but it wasn't feasable to switch back to my summer tires in Feb.

Nick

 

If you don't tow very much with it then you might be OK with a D rated tire. What type of ride quality problems are you having, is it just over bumps in the road or is it because it rides like a truck and not a car? BTW some people say installing new shocks help ride quality.

 

not actually 8 or 10 ply- really good thread on this a couple of days back.

 

on my second set of d rated tires- a total of 70,000 miles so far- no problems.

 

Though based on the old 8 ply and 10 ply system, the modern tires do not have that many plies. They are 2-3 ply sidewalls, but equal to the old system in strength.

If you do not pull trailers and never load the truck up, I would say go with the D rated. Should have no problems. Those that pull regularly, say, a heavy fifth wheel, will profess the need for an E rated tire (some desire the G rated Hankooks on the 19.5s).

 

TRC51... You are correct, but DBLR is correct as well.... Should you be loaded and have a tire failure, even if it is not because of the load, you could be in deep do do should it have to go to court. One of the first things checked in a major accident is vehicle equipment, tires, hitch rating, load, and so on and so on. Unfortunately we live in a very litigious society and I would not run "D" rated tires on my dually because I would not want to go through the gymnastics of proving it was not the tires ratings fault (If I could). Can you run the "D" tires? Most likely, there are may who do without incident. BUT... Me and Murphy are extremely close so I choose not to give some ambulance chasing legal hack anything to hang a fingernail on.
Just MHO... and we know they are like ..

 

Another thing to consider, my E rated BFG TA's are rated at 3095 Lbs.

So would you automatically assume one is safe based upon the E or D rating?

I personally would only run the E's, but it is not an indication that you are not overloaded.

 

I don't know if this is a fact, but because of tirelife I have always assumed the compound was a little harder on an e rated tire. I have had D and e rates and always gotten WAY better milage with the higher rated tire. I know that if you go to an F or G your milage will dramatically improve from an E.

Chris

 

After I wore out the stock "E" tires, I switched to the BFG 285 "D" that has a rating well over 3000. I pull an 11K toyhauler (tag) and find no real issue with the set-up other than it being a little softer, a little more squishy. I would attribute some of that to the sidewall density, and some to it just being a taller tire with more sidewall.

When out in the soft stuff, it is much easier to air up and down a 65 PSI tire rather than a 80PSI one, and the performance of the softer tire is better. If/when I go to a fiver, I'll go back to "E's", but the "D's" are good for now.

 

Not to single you guys out, but I am sick of seeing this on DTR. Lots of people here seems to say this, but have never offered up proof of this happening.
I claim its complete BS.

 

Maybe someone will chime in on this.

I have also heard those that pull commercially, or those that have been pulled over, they have scales which can read the weight on each axle. I don't think they care if it is a D or E rated tire, but they look at the weight and if you are over for that axle or tire, they will impound your vehicle. Has anyone actually had this happen to them? I have heard stories of it happening in Texas, and had a buddy driving a dually was pulled over in Utah when moving some John Deere tractors. My buddy was concerned because if he was over 26K lbs total weight he would have required a CDL, which he did not have (and he was not over that weight, luckily). But haven't heard of this happening lately?