Help me understand the CGVW on 2018 pickups

[Bobi and Dick McKee]

I was reading with interest about the new 2018 pickup specifications. Please don't flame me Im not knocking any brand and I still own a Ford.  The new F450 has an advertised CGVW of 41500 lbs.  That is 1500 more than a Freightliner M2.  How did they evolve the pickup from just over 30000 lbs CGVW a few years ago to over 40000 lbs?  I know it is a contest between the big 3 to be the bad boy on the block, I can't wrap my mind around how they justify the new  specs.

[I'mdonewiththis forum]

I have wondered the same thing. Looking at the new trucks, I don't know if I would feel comfortable with that much weight.

[Phil Saran]

Or the price tag on a new truck, $70-80K on up is a lot of $$$$ for a towing rig.

I can see where people end up buying a used over the road truck to haul a big RV.

[grumpydoc]

Depends upon which FL M2 you are talking about.  The M 2 112 with the DD 13 has 500 hp and 1850 torque.  With the 23K rear axle it is a legitimate class 7 truck.  With our 27K 5er we weigh in at 45K gross.  The truck handles it easily and with BleDot air/hydraulic stops it too.  Not brave enough to tow it with any class 4 truck and not about to let anyone else try! Best Wishes, Jay

[Alie&Jim's Carrilite]

Is there any difference in the diameter of the brake rotors from 3 years ago to these new truck?  If the rotor diameter is the same, and the same 2 piston calipers are there, then there isn't anymore braking capacity from the old to new.  I could make an old 5.9 Cummins run at 600 hp, 1100lbtq all day, but it still didn't stop for crap.  Even with aftermarket rotors, calipers, and pads.

[Kirk W]

I have a friend who used to tow his Mobile Suites with a Chevy Kodiak medium-duty truck but he traded it for a new F450 and reports that the Ford is handling his fiver better than the Kodiak ever did. But they price is pretty dear. 

[Bobi and Dick McKee]

Jay, I have all the confidence in the world in our M2. Ours has has the Cummins ISL9 with the Cummins engine mod to 385 hp and 1250 torque. It handles our 22k DRV like it isn't even back there.  My comment was that I don't understand how a 450 pickup of any brand has a 1500 lb greater tow capacity than an M2.  I suppose if you were to actually compare apples to apples and load a pickup down with a Trailer Saver hitch and 150 gallons of fuel like a stock M2 their tow capacity would drop.  Again not knocking any truck, just curious.  

[grumpydoc]

Bobbi/Dick, I agree, the hyper inflated ratings on new class 3 and 4 truck look like an invitation for potentially dangerous set ups.  Pulling a load is only part of the job as I see it, ascending and descending steep hills safely and panic stops can become life threatening challenges with heavy rigs.  Why are the Big Three advertising these high ratings, I don't know, but apparently their marketing dept must believe there is a market out there for them and legal must have signed off on it, would be my guess.  Kinda goes hand in hand with the new 5ers with the low pin weights, the "floaters"  as someone called them.  Another apparent attempt to exploit a perceived market, people who want bigger 5ers but don't want to move up to MDT/HDT tow trucks.  My guess is most of the people driving those rigs have never experienced a serious white knuckle event with an under sized truck.  It only took a couple to convince me to upgrade our truck, Best Wishes, Jay

[Gannet]

A question from someone who is not qualified to have an opinion: why do the truck brakes enter into it? Why don't the trailers have enough brake to take care of themselves?

[Alie&Jim's Carrilite]

9 minutes ago, Gannet said:

A question from someone who is not qualified to have an opinion: why do the truck brakes enter into it? Why don't the trailers have enough brake to take care of themselves?

All the SAE testing or whatever group that justifies the big 3 tow ratings only say the truck has to be able to stop a trailer that weighs 3500 lbs.   Basically a 1 axle utility trailer.  The trailer is SUPPOSED to stop itself, but what happens when it doesn't?  Can the truck stop the trailer your hauling in a panic stop without the trailer brakes working correctly?

What happens when you run over road debris- straddle it with the truck, but it rips out the electric brake wiring or the brake line tubing on hydraulic brakes?  I know what happens.... It happened to me ....  I was surrounded by flying debris from a rollover accident that happened directly in front of me at 65mph.  Nowhere to go but thru the accident in progress.  When the trailer brakes released it shoved us down the road over 1/4 mile.  I warped the front truck rotors and burned thru the Dodge 3500 brake pads trying to stop.  I was on the interstate and got lucky. 

What happens when your approaching an intersection and realize your trailer brakes have crapped out?  Can your truck stop you and your 20000-pound RV before you run over the Nuns escorting the kindergarteners across the crosswalk.....?

[Mark and Dale Bruss]

Actually in the determination of GCWR, the towed vehicle is assumed to have braking force for its weight.  The truck only needs to stop itself.  The truck needs to have enough engine power to get the combined vehicle up the on ramp.

This is how they have been able to radically increase the GCWR of pickups lately, the truck only need more horsepower and not brakes.

For a perspective, a single dual rear axle Class 8 truck has a GVWR of 32,000 lbs in most configurations.  Their GCWRs stay is the 80,000 to 120,000 range.

This only matters if trailer brakes never fail, but they do because they are not dual system like the tow vehicles.

[Alie&Jim's Carrilite]

Mark,

The failsafe of the trailer brakes locking with an airbrake system failure may flat spot some tires or cause other issues, but at least you know you have an issue... Might have to downshift the truck to get off the road though.

 

http://www.trucktrend.com/how-to/towing/1502-sae-j2807-tow-tests-the-standard/

Braking standards for the standards are near the bottom... 

 

 

Combination Braking Requirements

PERFORMANCE ATTRIBUTE	PERFORMANCE METRIC	REQUIREMENT
Combination Stability	Deviation within lane	Remain within a 3.5-meter-wide (11.5 feet) lane throughout stop
Combination Stopping Distance	Stopping distance 20-0 mph for TWR 3,000 pounds	≤35 feet, except ≤45 feet at any TWR above the tow vehicle’s unbraked TWR
Combination Stopping Distance	Stopping distance 20-0 mph for TWR 3,000 pounds	≤80 feet
Park Brake Performance	Hold on grade	12% grade at GCWR (upward and downward)

[Mark and Dale Bruss]

Air over Hydraulic and electric over hydraulic have a single point of failure, the hydraulic line.  I can attest that a break in that line means no brakes on the trailer. When that line goes, the truck needs to do all the stopping.

We are talking RV trailers here.

[grumpydoc]

Mark, I have to slightly disagree with you.  IMO, electric over hydraulic systems have two failure points, the electric component and the hydraulic component, which is why, in part, BluDot systems are more desirable, the air component is a more reliable actuator of the hydraulics.  Best Wishes, Jay

[Mark and Dale Bruss]

Now we are splitting hairs.  My response was to "The failsafe of the trailer brakes locking with an airbrake system failure".  In RV trailers, there is "at least" on singular point of failure.

My empirical experience was that the electrical didn't fail, the hydraulic line did.

[justRich]

On 10/26/2017 at 12:14 PM, Bobi and Dick McKee said:

I was reading with interest about the new 2018 pickup specifications. Please don't flame me Im not knocking any brand and I still own a Ford.  The new F450 has an advertised CGVW of 41500 lbs.  That is 1500 more than a Freightliner M2.  How did they evolve the pickup from just over 30000 lbs CGVW a few years ago to over 40000 lbs?  I know it is a contest between the big 3 to be the bad boy on the block, I can't wrap my mind around how they justify the new  specs.

I think, to address your question, that the engine power has increased substantially.  The pull vehicle is a lot lighter weight than the big rig that you mention.  The vehicle power to weight ratio maybe where to look for an answer.

In my opinion, today's pickups are crazy insane over powered for a daily driver.  My rig at 14,000 has the power of a modern car.  With the tow vehicle (5,050 lbs) it bogs down just a little.  The BIG difference is that these little powerful engines work well on the flats and hills, but going up hill, mine tends to overheat the oil.  (Coolant is fine)  GCVW at about 20,000 pounds.  

Coming up out of the Panamint Valley or crossing the continental divide during 80+ degrees temperatures will send the oil temperature over 240 degrees.  A long range pull like that in the summer, and I know that I'll have to pull over probably two times to avoid overheating the oil.
I've tried running at slower speeds (<55mph) but it still heats the oil.  I'm fine with using cautious prudence.

I'd like to see the big three show their rigs performance specs (coolant, oil, trans oil temps)  coming out of the Panamint Valley during summer.  

 

Braking: all systems are supposed to work.  Lets not talk failures.  There's a reason for run-away truck ramps.

[grumpydoc]

Mark, I understand  your point and am not trying to disparage it.  Simply wanted to point out that in most RV brake systems there is an electrical component, and there is no redundancy as you point out so a single failure totally disables the system.  In our 30 years of RVing we have had far more issues with the electrical component of our various rigs than the hydraulic.  My point that I was trying to make is that a system with two failure points would seem to have a higher chance of a failure than a system with one.   Since going to BluDot with our current rig we have eliminated the electrical component issues with our braking system.  Yes, you are right, we still have the risk of a single point failure of the hydraulic system,  but over the years the hydraulic brakes have seemed to be more dependable than electric.  No claims of expertise here, just some personal observations, Best Wishes, Jay