GVWR or GCWR which is more important?

[grogers]

I'm thinking about purchasing a 2108TB but concerned about my TV ability to handle it safely and without damage to my TV's engine, transmission and suspension. According to my figures; I would be using 97% of my GVWR (6200lbs) but only (80%) of my GCWR. (12,700lbs). I think I'm okay with my GCWR but concerned about using nearly all of my GVWR. Appreciate opinions and advice from experienced trailer folks.

[Morich]

One source of info that is far better than mine!

https://www.curtmfg.com/towing-capacity

[Goodspike]

First, what is a TV?

Second, assuming it's a tow vehicle, the GVWR is what the tow vehicle can weigh, including cargo and passengers and tongue weight of the trailer.

The GCWR is that the tow vehicle and trailer can weigh together.

Other important numbers are axle ratings and tow rating, although the latter is often exaggerated.

You can check most of your numbers (but not axle ratings) here.

[grogers]

Originally Posted by Goodspike

First, what is a TV?

Second, assuming it's a tow vehicle, the GVWR is what the tow vehicle can weigh, including cargo and passengers and tongue weight of the trailer.

The GCWR is that the tow vehicle and trailer can weigh together.

Other important numbers are axle ratings.

You can check most of your numbers (but not axle ratings) here.

Thanks Goodspike; TV is short for tow vehicle; also I understand what GVWR and GCWR mean. My main concern is using 97% of my TV GVWR; what do you think? If I had the option of hooking up a 2108TB to my TV with my wife and the 2108TB loaded before I buy I would do that; but I don't. My wife and me really like the 2108TB BUT we do not want to make a purchase and regret we did not purchase a 1706FB. I hope you understand where I'm coming from.

[Morich]

I'm not at all sure this will give you the real answer you need but part of my thinking may help. I look at these as two pieces, one how well the vehicle may move things forward and how it can wear heavy on it but the second is more where I get excited as it is what I might think of as how well it can stop things once we get moving.
So is it more important to almost max out the weight you can do a move or how well you can stop at 80 %?
I had a job where I had the biggest Suburban 4 wheel and towed a BIG generator which was well within both ratings. I could almost always depend on getting it going if not on ice or snow where I did sometimes need a tow truck but once moving, I really found out what the total stopping weight meant.
People have a bad habit of not wanting to stay behind a slow truck, so they often pass and then want to cut back in at stops, eating up the stopping space! If you've locked up the brakes on any truck and heard the reaction, you can guess how the driver feels when they have to take the shoulder to avoid creaming the guy who has cut in!
I don't worry about starting. I can take all day to get it up to speed but stopping has to be good and really good when you need it most.
Put a little rain, snow, or ice down and it gets really critical to have a vehicle big enough and heavy enough to not let the trailer jack the rear off the ground so you lose any traction. You may drive carefully but the folks all around you are likely not.

[grogers]

Richard, you make an excellent point about being able to stop. Something else I need to consider. Thanks for your insight.

[Goodspike]

Originally Posted by grogers

Thanks Goodspike; TV is short for tow vehicle; also I understand what GVWR and GCWR mean. My main concern is using 97% of my TV GVWR; what do you think? If I had the option of hooking up a 2108TB to my TV with my wife and the 2108TB loaded before I buy I would do that; but I don't. My wife and me really like the 2108TB BUT we do not want to make a purchase and regret we did not purchase a 1706FB. I hope you understand where I'm coming from.

Just checking--I thought TV could have been an abbreviation for some sort of German SUV.

I'm running pretty close to my GVWR, maybe 95%, so not quite as close. And I'm also well under my GCWR and tow rating.

I really think the GVWR is okay to push though, again as long as you're not over either axle ratings in doing so. It's really a combination of frame, axle and tire limits, so if it's balanced . . .. I'm within about 250 pounds of each axle's rating using a WDH, so I'm okay with that.

[creativepart]

Tell us what you are trying to tow with. That will help us answer the question. You kind of seem to be asking us to say it's okay to tow the bigger TT with a tow vehicle you already know is an issue.

[grogers]

Originally Posted by creativepart

Tell us what you are trying to tow with. That will help us answer the question. You kind of seem to be asking us to say it's okay to tow the bigger TT with a tow vehicle you already know is an issue.

Okay; my truck is a 19 GMC Canyon 2.8 Diesel, Crew Cab, 4x4, Short bed with the following numbers:
Maximum Tow Rated 7,600
GVWR 6,200
GCWR 12,700
Curb Weight (includes fuel) 4,940
Passenger & Cargo 430
Tongue Weight (includes trailer, hitch, battery, propane 615

Below are the numbers for the 2108TB:
Dry Weight 3,950
GVWR 7000
Tongue weight (dry) 435
Trailer Cargo (we go light) 400

GCWR 10,335 (total weight of truck and 2108TB)

I've seen many treads on this site and on U-tube that make me feel I will be okay but what concerns me is I'm using 96% of my trucks GVWR if I buy a 2108TB. However, I'm only using 57% of my trucks maximum tow rating. This stuff is so confusing it makes me think I should just buy a boat and go fishing. To everyone have a good day.

[Goodspike]

I have the basically the same tow vehicle (but the Chevy version) and a 2106DS. That tongue weight seems a bit high--mine is only a bit higher with tanks and batteries loaded.

But anyway, I would suspect you could get the same balance I do with a proper WDH setup. And yes, this is an example of tow ratings being complete BS. I don't know how you could possibly tow a 7,600 pound trailer and be within other specs. Maybe a boat trailer?????

[grogers]

Originally Posted by Goodspike

I have the basically the same tow vehicle (but the Chevy version) and a 2106DS. That tongue weight seems a bit high--mine is only a bit higher with tanks and batteries loaded.

But anyway, I would suspect you could get the same balance I do with a proper WDH setup. And yes, this is an example of tow ratings being complete BS. I don't know how you could possibly tow a 7,600 pound trailer and be within other specs. Maybe a boat trailer?????

I totally agree and after much research I'm beginning to understand why new buyers get stuck with trailers their tow vehicles cannot handle well. Yesterday, on the interstate, I passed a guy towing a trailer that was swaying a bit and he was only going 40-50 mph. It was a bit windy (20 mph) but he was struggling to keep his rig in a lane. I would hate to buy a trailer and be in the same situation. Take care and have a great weekend.

[DavidM]

I look at GVWR as mostly related to stresses on the suspension, wheel bearings and frame. GCWR is mostly related to stresses on the engine and transmission as well as braking.

I think that approaching or exceeding the GVWR is much more forgiving than approaching or exceeding the GCWR.

David

[Goodspike]

Originally Posted by DavidM

I look at GVWR as mostly related to stresses on the suspension, wheel bearings and frame. GCWR is mostly related to stresses on the engine and transmission as well as braking.
David

I'd substitute axles for wheel bearings, but I like that analysis.

[grogers]

Originally Posted by DavidM

I look at GVWR as mostly related to stresses on the suspension, wheel bearings and frame. GCWR is mostly related to stresses on the engine and transmission as well as braking.

I think that approaching or exceeding the GVWR is much more forgiving than approaching or exceeding the GCWR.

David

Thanks David; that is pretty much what Goodspike mention too. I appreciate both of your thoughts on my concerns. Perhaps, the 2108TB is still in my future.

[NXR]

Originally Posted by DavidM

I look at GVWR as mostly related to stresses on the suspension, wheel bearings and frame. GCWR is mostly related to stresses on the engine and transmission as well as braking.

I think that approaching or exceeding the GVWR is much more forgiving than approaching or exceeding the GCWR.

GVWR also includes braking ability so 97% is getting touchy to me, especially if the trailer will be towed down long hills.

While the trailer will have its own braking system, who knows how much it really helps? If it's misadjusted or worn then the trailer brakes may not be helping as much as you think. If the tow vehicle's brakes are well-worn it wont have full braking ability. Etc.

Ray

[Goodspike]

Originally Posted by NXR

GVWR also includes braking ability so 97% is getting touchy to me, especially if the trailer will be towed down long hills.

While the trailer will have its own braking system, who knows how much it really helps? If it's misadjusted or worn then the trailer brakes may not be helping as much as you think. If the tow vehicle's brakes are well-worn it wont have full braking ability. Etc.

Ray

The OP's truck has an exhaust brake, so that shouldn't really be an issue. The diesel engine shuts down the turbo vanes somehow, creating back pressure which slows the vehicle. Much better than just engine braking. Works really well. Going down the west side of Snoqualmie pass, which isn't all that steep but very long, I often had to accelerate to maintain speed with the exhaust brake on.

Also with a tandem axle trailer having four sets of brakes . . ..

And finally, it's the GCWR that would be more important for braking. He's well under that limit.

[NXR]

Originally Posted by Goodspike

The OP's truck has an exhaust brake, so that shouldn't really be an issue. The diesel engine shuts down the turbo vanes somehow, creating back pressure which slows the vehicle. Much better than just engine braking. Works really well. Going down the west side of Snoqualmie pass, which isn't all that steep but very long, I often had to accelerate to maintain speed with the exhaust brake on.

Also with a tandem axle trailer having four sets of brakes . . ..

Thanks for the info on the exhaust brake; I did not catch that. Perhaps not unexpectedly, the last link below does not give any allowance for any type of assist systems when testing the service brakes for vehicle certification.

And finally, it's the GCWR that would be more important for braking. He's well under that limit.

I guess this will have to be one of those "Agree to disagree" items.

https://www.weigh-safe.com/towing-sa...weight-rating/

It is also important to note that the brakes on the tow vehicle are only rated for the GVWR and not the GCWR.


This is one of the better articles i've read on towing capacities and all of the considerations.:

https://fifthwheelst.com/A-Lesson-on...ting-GCWR.html

The GVWR, as required by National Highway Traffic Safety Administration (NHTSA), primarily considers the weakest link in the load bearing components such as the frame, axles, springs, brakes, rims, and tires. Based on the lowest component rating within the load bearing components, manufactures assign the GVWR. One of NHTSA's safety requirement for GVWR is that the vehicle is expected to stop within a required distance when it is fully loaded to the max GVWR. This appears to be a primary safety concern of NHTSA when tow vehicles are overloaded by too much pin or tongue weight coming from the trailer. Some owner's manuals clearly state:

"The towing vehicle's brake system is rated for operation at the GVWR—NOT GCWR. Separate functional brake systems should be used for safe control of towed vehicles and for trailers weighing more than 1,500 lbs. when loaded."


This is a reg on testing braking systems. All references are to GVWR. References to GCWR, trailer, or towing do not appear at all.

https://www.govinfo.gov/content/pkg/...sec571-105.xml

S5.1.1Stopping distance. (a) The service brakes shall be capable of stopping each vehicle with a GVWR of less than 8,000 pounds, and each school bus with a GVWR between 8,000 pounds and 10,000 pounds in four effectiveness tests within the distances and from the speeds specified in S5.1.1.1, S5.1.1.2, S5.1.1.3, and S5.1.1.4.

(b) The service brakes shall be capable of stopping each vehicle with a GVWR of between 8,000 pounds and 10,000 pounds, other than a school bus, in three effectiveness tests within the distances and from the speeds specified in S5.1.1.1, S5.1.1.2, and S5.1.1.4.

(c) The service brakes shall be capable of stopping each vehicle with a GVWR greater than 10,000 pounds in two effectiveness tests within the distances and from the speeds specified in S5.1.1.2 and S5.1.1.3.

Knowing how my reaction times have slowed over the years and having worked in the safety fields for many years I know how things can go wrong at the wrong time too often. For me, presuming that every other system of the vehicle is performing in "like new" condition is just something I do not do.

FWIW,

Ray

[Goodspike]

Originally Posted by NXR

It is also important to note that the brakes on the tow vehicle are only rated for the GVWR and not the GCWR.

I don't think that's true at all. GVWR is based largely on axle, suspension and tire issues, but in addition, for GM full size trucks (Silverados) they require trailer brakes only for vehicles over the 2,000 pounds. That means you could have a vehicle carrying its GVWR and an additional 2,000 pounds using only the truck's brakes. So the brakes are clearly rated for more than GVWR. And seemingly the need to add trailer brakes is more dependent on when the trailer will become unwieldy without brakes since it's not a percentage of GVWR.

I don't think anyone is arguing that you should exceed any of the three weight limits. But if my truck only weighed 5,700 pounds when connected to a trailer (curb weight, me and 700 pounds tongue weight), well below it's 6,200 GVWR, it would stop slower if it's GC weight was 10,700 pounds, than if it was fully loaded at 6,200 pounds and the GC weight was only 9,700 pounds. So pushing the GVWR by itself would not have an adverse impact on braking. If I somehow managed to tow a total weight of 12,700 pounds (my GCWR) my braking would be greatly affected.

[grogers]

I would have to agree with Goodspike on the braking issue. One thing to note that my TV owners manual hardly mentions braking; all it says is never exceed the vehicles GVWR, GCWR and tongue weight. Afterall; when towing; not only do I have my vehicles brakes plus an exhaust brake and my trailer has it's own brakes. Stopping does not totally depend upon my vehicles regular brakes. I recently borrowed a friends 4900 lb camping trailer equipped with a weight distribution hitch and hooked up to my Canyon. We went to a certified scale and found that my truck weighed 5820 and the trailer weighed 4040 for GCWR of 9860. Since my trucks curb weight is 4940; we figured that 860 lbs of the trailer was transfered to my truck by the WDH. We then towed the trailer for 200 miles without any difficulty towing or stopping. There was a 20 mph wind and did experience some trailer sway above 65 mph. His trailer has a larger wind profile compared to a 2108TB. Also, considering his trailer is 1000 lbs heavier I think the 2108TB will be okay. I was impressed with how my Canyon towed this larger trailer. It is amazing what 4 cylinders can do.

[Goodspike]

Originally Posted by grogers

One thing to note that my TV owners manual hardly mentions braking; all it says is never exceed the vehicles GVWR, GCWR and tongue weight.

There are the towing guides which say more.

https://www.chevrolet.com/truck-life...d-towing-guide

It is amazing what 4 cylinders can do.

It's amazing what diesel can do.