Pickup truck tow vehicle stability tests

AH64ID wrote:

NC Hauler wrote:


...and as you can see Ben, it was STILL questioned....so even the dumbing down doesn't seem to help much......too simple evidently.....

as stated also, common sense isn't very common anymore.....

Nope, but we can't all be like you and your apple to oranges logic.

Provide a link that actually applies to the physics being discussed, not the physics in your mind. But hey if you think it really applies....

There is very little in that link that actually applies to the differences in SRW vs DRW in normal driving... getting rid of tailgaters aside.

I'm an old Engineer..at almost 65, got my degree quite some time ago, so guess things have changed since then. I like that, "Physics in my mind":)...don't use some of the physics like I used to when I was in designing, (ie, R&D), but not much has changed in the world of physics for quite some time.

I'm tiring of the discussion, you can win this one, seems like you need it more than I do...I know what I know from a lot of research and lot of towing over the last 40 years, but it used to be, "experience speaks volumes",, or "experience is the best teacher", just doesn't apply in some places......believe what you want....I know the same numbers you do...but guess it's "all in my mind", (thank the Lord it's still working:)).

AH64ID wrote:

Heck my 3500 SRW has a higher tow rating than a DRW of the same year/gear. It just depends on what is being towed if you can actually get there with a stock SRW.

Page 9 PDF

Translation is the 3500 SRW quad cab 4x4 is GVWR 9900, payload 3020
GCWR is 23000 and trailer towing is 15950.

The Ram dually 3500 DRW quad cab 4x4 is GVWR 12200, payload 4840,
GCWR is 23000 and trailer towing is 15500.
This means the unladen weight is 450 more for the DRW thus the less trailer towing rating.
Of course you have added the 19.5 rubber which increases your figures greatly.

NC Hauler wrote:


...and as you can see Ben, it was STILL questioned....so even the dumbing down doesn't seem to help much......too simple evidently.....

as stated also, common sense isn't very common anymore.....

Nope, but we can't all be like you and your apple to oranges logic.

Provide a link that actually applies to the physics being discussed, not the physics in your mind. But hey if you think it really applies....

There is very little in that link that actually applies to the differences in SRW vs DRW in normal driving... getting rid of tailgaters aside.

The rugby player analogy would only apply if the springs moved outward with the stance. The Rugby player is moving his pivot point wider, but a DRW doesn't change the pivot point.

The stool sample only applies if you have removed the suspension on your truck and have the axle directly mounted to the frame.

But of course your common sense told you all that right?

NC Hauler wrote:

AH64ID wrote:

Cummins12V98 wrote:

goducks10 wrote:
So it boils down to a wash depending on who you agree with. And add into it that a 2500 is the same as a 3500 sans rear springs. So in that sense a 2500 could tow what a DRW does. That makes sense doesn't it? :)

In the 13 and up RAM trucks the 2500 SRW is not the same as the 3500 SRW.

No it's not, thou the frame is still the same and the axle is still overkill... no real difference for the end user in the AAM 11.5 vs 11.8... so in a way his statement isn't too far off. Springs/Suspension is the biggest different.

No easy way to tell what that 2500 suspension can really handle thou.

per AAM, 11.5 rated for 11,500# for the 11.8 it's 11,800# per AAM, but heck, they may have lied about it...and if one compares the spring pack of a 2500 to a 3500 dually...er WOW, HUGE difference. BIG difference as you stated with front and rear suspension, and enough to MAKE a BIG difference in GVWR difference from a 2500 of 10,000# to a 3500 dually with 14,000#....yeah, I know the dually is heavier, that's "kinda obivious"...and only 3500 SRW and 3500 DRW get the Aisin transmission which means more HP and more TQ., and only dually get's the 3:42, 3:73 and the 4:10, which gives more and more GCWR...mine is rated at GCWR of 37,500#, but it's 2 yrs old...

Yes there is a small difference, but it won't effect the end user as I stated.

Where did you get 11,500# from? AAM told me 4950 kgs, which is 10,912lbs. I know you got the 11.8" specs from them, so I would guess that is where you got the 11.5" specs... I suspect they told one of us bogus numbers. Either way the ratings are well above the RAWR on any Dodge/Ram that uses the AAM 11.5" or 11.8" axle.

When there was a spring pack difference between 2500 and 3500 there wasn't that much difference in the main leafs. There was a design difference 4/1 on the 2500 and 3/1 on the 3500 but there was only a 7% difference in ratings. The overloads do add a decent amount, as they carry a rating of about 46% of the main pack meaning the DRW has 57% more capacity in terms on lb/in. That is once the overloads engage. On my 4/1 leaf pack (3500 SRW) I have to be above 6K lbs on the rear axle to get the overlaods to engage. Now that there isn't a spring pack on the 2500 it's harder to compare.

Front suspensions are the same 2500 thru 3500 DRW in 14+, the only year they were different was 13.

I have always said that the GVWR ratings between 2500, 3500 SRW, and 3500 DRW are about marketing first and capability second. A 2500 and 3500 SRW both have the same actual limit, the tires, but the RAWR, GVWR, and GCWR are different... that's a marking difference. Why does a 3500 SRW have a 12,300lb GVWR when the FAWR+RAWR=13,000 and the frame is the same as the 14K lb GVWR DRW? Simple.. the SRW has to be rated lower than the DRW. Why is the DRW (FAWR+RAWR=15,750) limited to 14K GVWR? To be a Class III pickup.

If Ram were to discontinue the 3500 SRW tomorrow I would be willing to bet the 2500 numbers would change to match the 3500 SRW numbers without any physical differences (except that 18's would be standard instead of an option to allow for the 7K RAWR). Zero axle or suspension changes would be necessary.

Sorry for the derail, I find these conversations interesting and enjoyable.

NC Hauler wrote:
wished I'd just purchased a nice 2500, it'll do everything my 3500 dually will do...cept for payload, cept for RAWR, cept for GCWR, but other than that.....they're the same:)

There are distinct differences, and not all of them account for the difference on paper... but many of them will make for an easier driving experience. The J2807, which is a great test, gives DRW vehicles easier requirements to meet. It's one reason that a DRW vs a SRW with the same powertrain/gears can be rated higher. Nothing wrong with it, just need to know that if you were to have a DRW rated at 27K lbs towing and a SRW rated at 27K lbs towing the SRW would have more power to meet the SRW requirements, and would out accelerate and hold speeds better than the DRW.

BenK wrote:
45...thank you for the British link...proof in that link (11-14 year
old school course work in physics...AKA Science) that the dumbing down
of folks is true...

Repeat (2nd time) that common sense is very UN-common...

AH64ID wrote:

NC Hauler wrote:

45Ricochet wrote:
LINK :B

Don't know if you could get more basic or simpler than that Rick:B

ON EDIT: BUT..if the legs on the wider table are weaker than the one on the narrower table...it would...uh, never mind:)

Very simple page... but unless you guys all drive around with your inside tires in the air it doesn't apply.

Where does the truck pivot? The springs, which are the same width SRW to DRW. Increased spring rate, higher on a loaded DRW than a loaded SRW, is a big increase in stability.

...and as you can see Ben, it was STILL questioned....so even the dumbing down doesn't seem to help much......too simple evidently.....

as stated also, common sense isn't very common anymore.....

45...thank you for the British link...proof in that link (11-14 year
old school course work in physics...AKA Science) that the dumbing down
of folks is true...

Repeat (2nd time) that common sense is very UN-common...

PS...I do get my 2 seater's inside radius tires off the ground
and sometimes 'think' my Sub's too (can't see'm)...when some latest
and greatest TV tail gates me thinking they will show me...take them
into a curve way faster than they can...after checking in the mirror
of what they got (track is the main)

AH64ID wrote:

NC Hauler wrote:

45Ricochet wrote:
LINK :B

Don't know if you could get more basic or simpler than that Rick:B

ON EDIT: BUT..if the legs on the wider table are weaker than the one on the narrower table...it would...uh, never mind:)

Very simple page... but unless you guys all drive around with your inside tires in the air it doesn't apply.

Where does the truck pivot? The springs, which are the same width SRW to DRW. Increased spring rate, higher on a loaded DRW than a loaded SRW, is a big increase in stability.

Huntindog wrote:

valhalla360 wrote:

RinconVTR wrote:

valhalla360 wrote:

RinconVTR wrote:
Take the stability of 2 rear tires and multiply by two...give or take.

OP, am we missing something? Is there a hidden question here?

Wow, not even close to reality. By this logic is we fit the entire length of the axle with tires (say 8 tires) it will be 8 times as stable (it's not).

The answer is yes, dually's are more stable but as long as you are within weight ratings, there is no safety issue. SRW trucks don't fall over because they are missing the training wheels. You would be very hard pressed to document a situation where a SRW would roll but a dually would stay upright while towing.

I suggest you start watching semi's. You will notice a great many are going singles (a little difference as the outside width is held steady). If they were falling over left and right, trucking companies wouldn't use them. That is about as objective as you can get on the subject.

The reason to get dually's is because you need the extra load capacity.

Question was about stability...not load...not safety...stay on topic. You answered the question yourself...but yet you go on.

If you look at the trucks converting from dual to single tires, they are not carrying the highest loads and the single tire is VERY wide. VERY WIDE! Now why would they do that? Hmmmm

Also stability while towing...IMO...does not mean resistance to tip over. Roller over "stability" I don't believe was the point of discussion here, but if it was, I'd simply take measure. The wider version likely wins. And is that not the dually?

Safety was implicit in the question. If the OP wasn't concerned with safety, what would be the point of the question?

To end it as yes, it's stable and ignore the fact that there is no distinguishable benefits (other than load ratings), would be highly misleading, so I took the liberty of adding to the discussion.

Supersingle truck tires are very wide. They are very wide so they can handle heavy loads not to make the truck more stable. I brought it up because there were misleading posts that more than one tire is intrinsically more stable.

True, stability could be in reference to either roll overs or the trailer pushing the back of the truck around:
- For roll over, there is an improvement but as stated, there's not a problem with SRW trucks towing 5th wheels falling over. The impact while towing is negligible and well within safe operating parameters.
- For stability in reference to the trailer pushing the rear of the truck around, there is even less effect (not that 5th wheels typcially have an issue with this anyway). There may be a couple hundred pounds from the extra tires, axle length and such but overall the weight planted on the rear axle but it's going to be pretty close to the same for a similarly outfitted rig. Available traction is a function of the coefficent of friction and the force pressing the wheels to the ground. If they are the same, there would be no additional stability. Any negligible difference could be made up by throwing some extra weight in the truck bed.

So my initial answer still stands. There is a difference but not enough to matter.

It's about standards.
Some people are perfectly happy with a less than ideal setup... And not just in this discussion about trucks either... All the way down to the guy towing with a Prius.

If you are happy with your setup, then I guess I am happy for you.

If you are exceeding the tow ratings, definitely move up to the heavier duty truck. I believe I said that 3-4 posts ago.

But if you are within ratings, that is like saying you need a 1 ton dually to be safe pulling a popup. Certainly it will pull it with ease but it's really rather silly waste of the trucks capabilities.

AH64ID wrote:

Cummins12V98 wrote:

goducks10 wrote:
So it boils down to a wash depending on who you agree with. And add into it that a 2500 is the same as a 3500 sans rear springs. So in that sense a 2500 could tow what a DRW does. That makes sense doesn't it? :)

In the 13 and up RAM trucks the 2500 SRW is not the same as the 3500 SRW.

No it's not, thou the frame is still the same and the axle is still overkill... no real difference for the end user in the AAM 11.5 vs 11.8... so in a way his statement isn't too far off. Springs/Suspension is the biggest different.

No easy way to tell what that 2500 suspension can really handle thou.

per AAM, 11.5 rated for 11,500# for the 11.8 it's 11,800# per AAM, but heck, they may have lied about it...and if one compares the spring pack of a 2500 to a 3500 dually...er WOW, HUGE difference. BIG difference as you stated with front and rear suspension, and enough to MAKE a BIG difference in GVWR difference from a 2500 of 10,000# to a 3500 dually with 14,000#....yeah, I know the dually is heavier, that's "kinda obivious"...and only 3500 SRW and 3500 DRW get the Aisin transmission which means more HP and more TQ., and only dually get's the 3:42, 3:73 and the 4:10, which gives more and more GCWR...mine is rated at GCWR of 37,500#, but it's 2 yrs old...

AH64ID wrote:

Cummins12V98 wrote:
When traveling West on I-10 where the windmills are with the SRW I could feel the wind whenever it was blowing. With the Dually I rarely feel the wind there I have to look at the foliage along the road to see if it is windy.

Which is interesting, as I rarely feel the wind in my SRW. The only time I can really feel it is when there are large gust spreads... which are the same kind of gusts that I feel towing or not, and the kind that will actually try to open the door with the wind across the roof.

goducks10 wrote:
So it boils down to a wash depending on who you agree with. And add into it that a 2500 is the same as a 3500 sans rear springs. So in that sense a 2500 could tow what a DRW does. That makes sense doesn't it? :)

Heck my 3500 SRW has a higher tow rating than a DRW of the same year/gear. It just depends on what is being towed if you can actually get there with a stock SRW.

I have no clue what an 05 3500 SRW truck could tow or an 05 DRW truck (Dodge), could tow..but I DO know that there IS a difference between the NEWER 13's and up's..and a 2015 Ram 3500 SRW truck with 3:42 can't touch what my dually with 4:10 can tow....

Most are talking new/newer trucks now, unless someone comes along to compare older model trucks....
Goducks pretty much hit it...yeah per most who own a 2500, it's EXACTLY the same as a 3500SRW truck.....soo......and of course the 3500 SRW truck is the same as a dually, except for the 4 wheels:R...don't know much about Ford or Chevy now, but one can crawl underneath a new Ram 2500, Ram 3500 SRW and a new Ram 3500 dually and literally SEE a difference, but no one is going to believe that....wished I'd just purchased a nice 2500, it'll do everything my 3500 dually will do...cept for payload, cept for RAWR, cept for GCWR, but other than that.....they're the same:)

Cummins12V98 wrote:

goducks10 wrote:
So it boils down to a wash depending on who you agree with. And add into it that a 2500 is the same as a 3500 sans rear springs. So in that sense a 2500 could tow what a DRW does. That makes sense doesn't it? :)

In the 13 and up RAM trucks the 2500 SRW is not the same as the 3500 SRW.

No it's not, thou the frame is still the same and the axle is still overkill... no real difference for the end user in the AAM 11.5 vs 11.8... so in a way his statement isn't too far off. Springs/Suspension is the biggest different.

No easy way to tell what that 2500 suspension can really handle thou.