Ultimate payload monster?

[Hemling]

What do you think is the top payload rating among new one-ton trucks? All the advertising goes toward horsepower/torque and towing capacity, but what configuration is king of payload?

[RoyJ]

noteven wrote:
Class 8’s are engineered individually on a per order basis by the factory applications engineering group working with the dealer sales person who works with the customer.

As mentioned by others a large number of factors are involved in a spec.

This applies more to heavy haul customers, like specialized C500s and T800s with enlarged radiators, hub reduction axles, that get used to haul transformers and power plant structures.

For a run of the mill OTR Class 8, I see 2 main classes: 80 - 90k GVW line haul, where hwy fuel efficiency rules; and flatbed / "heavy haul", with mid rise sleepers and steeper 46k rear ends. This probably covers 90% of your fleet / owner op purchases.

Here in BC tridems are popular, as we don't allow lift axles. They're in their own niche, not quite as heavy as real heavy haulers, but heavier than typical flat bed spec. They're usually T800s or Western stars with the largest radiator without going super wide hood.

[RoyJ]

blt2ski wrote:
Roy,

Scooby/noteven probably said it better than me. In that GCVWR is based, speed etc on the end users needs. Shiner hinted when he mentioned truck used in a mine get speed with heavier duty components, yet on the road, they can't haul that amount due to road bed design limits.
This mine rigs lig garbage trucks might also have a gradubikity of 100% ie 45 degrees. A typical otr rig will be stalled out on a 15-20% grade. Pickups are only required to be a min if 12%, doesn't do me a lot of good sitting her in front of my sister's with a full load on an 18% grade. Or a past client who's driveway was 30%. I can't go up those grades unless I back track on pickup GCWR ratings, deduct for hight grades
Pkud HP ratings on a truck can be deducted 30% if a given truck has a full aero PKG, plus 30% is needed if hauling a trailer like a log truck, chicken hauling rig, as wind resistance is way higher then they will use actual frontal area, not just 80 sq ft, with no deduction if your hauling a 120 sq ft trailer behind your pickup.
Reality, I'm hitting the tip of the iceberg in how much different pickups vs heavy duty rigs are speed to do there jobs. I've stalled out multitudes if pickups on local steep grades, u set rated GCWR. I've seen an 18 wheeler that did 60 mpg from Louisiana to Wa st, stall out on one of our fun local 20% grades. A mile from it destination...
This is why I bought the Navistar I've an equal GM it Ford. They gave me the what and how it would handle what I was doing, vs a shrug of shoulder, wave of hand, no problem!
Any way, time to go cut some wall block caps finish what I'm doing here

Marty

Makes sense, if there's no universal industry standard, then GCWR becomes more a marketing number than engineering spec, hence less used in the commercial world.

With pickups, if we allow the use of 4 Lo, their gradability is right up there with the best of vocational trucks. Assuming perfect surface with a friction coefficient of 1.0, modern diesel pickups can easily generate tractive effort = GVWR in 4Lo.

So let's say a Ram 3500 with 14,500 GVW generates 14000 lbs of tractive force. With a 37k GCW, that's 38% gradability. A 5500 @ 19,500 GVW, but same GCW, would have 53%.

In a b-train, my limit is often traction. 38k lbs on drives with a GCW of 140k lbs, gradability maxes out at 27% regardless of gearing / engine torque.

[BenK]

Payload will always be = TV's actual weight on the rear axle while fully loaded, ready to go RV'ing...subtracted from the TV's RGAWR = payload

As 'most' TV's will carry their loading over the rear axle, because most of the things loaded into the TV is forward of the rear axle.

Notice where the rear edge of the driver's door is. Most are smack in the middle of the wheelbase...even crewcabs

Hemling wrote:
What do you think is the top payload rating among new one-ton trucks? All the advertising goes toward horsepower/torque and towing capacity, but what configuration is king of payload?

[blt2ski]

Roy,

Scooby/noteven probably said it better than me. In that GCVWR is based, speed etc on the end users needs. Shiner hinted when he mentioned truck used in a mine get speed with heavier duty components, yet on the road, they can't haul that amount due to road bed design limits.
This mine rigs lig garbage trucks might also have a gradubikity of 100% ie 45 degrees. A typical otr rig will be stalled out on a 15-20% grade. Pickups are only required to be a min if 12%, doesn't do me a lot of good sitting her in front of my sister's with a full load on an 18% grade. Or a past client who's driveway was 30%. I can't go up those grades unless I back track on pickup GCWR ratings, deduct for hight grades
Pkud HP ratings on a truck can be deducted 30% if a given truck has a full aero PKG, plus 30% is needed if hauling a trailer like a log truck, chicken hauling rig, as wind resistance is way higher then they will use actual frontal area, not just 80 sq ft, with no deduction if your hauling a 120 sq ft trailer behind your pickup.
Reality, I'm hitting the tip of the iceberg in how much different pickups vs heavy duty rigs are speed to do there jobs. I've stalled out multitudes if pickups on local steep grades, u set rated GCWR. I've seen an 18 wheeler that did 60 mpg from Louisiana to Wa st, stall out on one of our fun local 20% grades. A mile from it destination...
This is why I bought the Navistar I've an equal GM it Ford. They gave me the what and how it would handle what I was doing, vs a shrug of shoulder, wave of hand, no problem!
Any way, time to go cut some wall block caps finish what I'm doing here

Marty

[noteven]

Class 8’s are engineered individually on a per order basis by the factory applications engineering group working with the dealer sales person who works with the customer.

As mentioned by others a large number of factors are involved in a spec.

[JRscooby]

RoyJ wrote:



Hmm, that's something new to me. I did some Googling, and so far only found GCWR on Volvo tractors.

I went to Kenworth, on their MDs for example, it stated the transmission is rated to 58k lbs GCWR:



But Googling W990 GCWR showed no such spec:



The only tractor with a GCWR is their C500 heavy hauler, at 1/2 million lbs. But I guess that's a specialized tractor.

My thought is most Class 8 tractor components have GCWR well beyond hwy GVW limits, so they don't bother listing. Here in BC GVW maxes out at 140k lbs, and I've hauled nearly that in a run of the mill Freightliner with 46k rears.

Most order sheets I have looked at for class 8 trucks list the GCVWR as "to customer specifications". Now it is likely that Volvo, and to a lesser extent International, that produce mostly for fleets, have a standard they are willing to advertise

[RoyJ]

blt2ski wrote:
Roy,

Larger trucks do and will have GCWR ratings per say. Not like pickups in that their is a single rating.
A given chassis drivetrain may have multiple ratings depending upon the end users needs. If used as a local delivery, gcw might be lower than an otr setup. Because local needs and wants say a 20-25% gradability, only 55 mph speeds on freeway. Meanwhile the otr setup wants 60mph, and only a max 15% gradeabilty.
It ultimately does get down to axle gears, tire diam, HP, torque, transmission gears ratios, number of gears....
Some rigs line my Navistar, reality is it's never supposed to be going down the road beyond manufactures gvw if 18200. Alot of us push this motor local deliver to 26000. It does not do real well beyond that. Even if it's level.

Marty

Hmm, that's something new to me. I did some Googling, and so far only found GCWR on Volvo tractors.

I went to Kenworth, on their MDs for example, it stated the transmission is rated to 58k lbs GCWR:

https://www.kenworth.com/about-us/news/kenworth-launches-new-medium-duty-product-lineup/

But Googling W990 GCWR showed no such spec:

https://www.google.ca/search?safe=off&sxsrf=ALeKk02EByApU8ScfnzYBwmLiAxqgah2BA%3A1596872753469&sourc...

The only tractor with a GCWR is their C500 heavy hauler, at 1/2 million lbs. But I guess that's a specialized tractor.

My thought is most Class 8 tractor components have GCWR well beyond hwy GVW limits, so they don't bother listing. Here in BC GVW maxes out at 140k lbs, and I've hauled nearly that in a run of the mill Freightliner with 46k rears.

[noteven]

noteven wrote:
RV pickup driver: "I scaled at the CAT scale at 30,921lbs so I'm just over GCWR blah blah blah towin heavy blah blah lot's of power blah blah...air bags blah blah..."

Driver of Kenworth heavy haul tractor, standing by his 220,000lbs GCWR load:

Ozzie road train driver:

[blt2ski]

Roy,

Larger trucks do and will have GCWR ratings per say. Not like pickups in that their is a single rating.
A given chassis drivetrain may have multiple ratings depending upon the end users needs. If used as a local delivery, gcw might be lower than an otr setup. Because local needs and wants say a 20-25% gradability, only 55 mph speeds on freeway. Meanwhile the otr setup wants 60mph, and only a max 15% gradeabilty.
It ultimately does get down to axle gears, tire diam, HP, torque, transmission gears ratios, number of gears....
Some rigs line my Navistar, reality is it's never supposed to be going down the road beyond manufactures gvw if 18200. Alot of us push this motor local deliver to 26000. It does not do real well beyond that. Even if it's level.

Marty

[RoyJ]

JRscooby wrote:
Tractors, and class 8 trucks do in fact have GVWR/GCVWRs plus axle weight ratings.

Very rare to see GVWR, as it's almost always sum of axle ratings. GCWR? I've only seen it on individual components, like a transmission, almost never on a full chassis truck.

And I have moved more than a few permit loads. And when you run up on a scale, they will check the weight on each axle/axle group. But they don't look at the axle ratings. What they do look at is tire ratings.
Then there are other things driver needs to know about where he can haul weight. In my area, a tri-axle dumptruck can be legal, cross a line on the map, and be $3,000.00 plus court cost overweight.
A overweight permit for your 3500? In my state they would tell you to just buy the license for what you want to gross. Years back a friend sent his girl to license office to renew plates on his 7 class 8 Macks, and buy the plates for his new Dodge 3500. She came home with 8 80,000 lbs local plates

You took my overweight permit on a pickup example way too literal...

In case my point wasn't clear: recreational haulers treat OEM GVWR and GCWRs as laws of physics limits. Exceed by 100 lbs, all of a sudden you lose control of your truck.

Actual DOT enforcement focuses a LOT more on legality, than OEM performance specs. As you said, the only thing they care about is tire ratings, which is not even an OEM spec.

[Grit_dog]

dodge guy wrote:
Best thing to do is load it till it breaks. Then go out and buy the same truck and back it off a few pounds so it won’t break.
Jeez, why does everything need to be to complicated!

Ha, while tongue in cheek, you’re sort of on the right track, theoretically.
And while many folks here vehemently disagree with my recommendations, they come from exactly what you said.
After many years in my career paths, I’ve fixed, or seen what breaks or broken many light duty trucks and have a pretty solid feel for what they’ll handle.
If more folks were more observant of others (great place to learn is by others successes and failures) and at least mildly engaged in what their vehicles were “telling them”, many of these questions or fears would be answered

[noteven]

RV pickup driver: "I scaled at the CAT scale at 30,921lbs so I'm just over GCWR blah blah blah towin heavy blah blah lot's of power blah blah...air bags blah blah..."

Driver of Kenworth heavy haul tractor, standing by his 220,000lbs GCWR load:

[Groover]

Around here the word is that police don't check single rear wheel trucks in commercial use. As a result a lot of people are running single rear wheel trucks when the world would be safer with them running duals. I know a guy that uses a 10 year old F250 gasser to pull a tandem dually dump trailer for his business. He frequently loads the trailer to the hilt but never gets stopped. That truck is a real testimony to the amount of abuse that Ford's 6.2 gas drivetrain can take.

[dodge_guy]

Best thing to do is load it till it breaks. Then go out and buy the same truck and back it off a few pounds so it won’t break.
Jeez, why does everything need to be to complicated!