CAT Scale weights are confusing me.

[Atlee]

Weighted my truck and trailer Friday, before we went on a weekend camping trip. The trailer is brand new. It had never been out camping before.

My WDH is the Blue OX Sway Pro. With 1k bars. I put it up to the 9th Chain link as called for in the book, and the Tech who installed the the Blue Ox
First, my TV is a 2014 F150 XLT 4x4, Supercab, 8 ft box, with Max Tow Package, and the HDPP. The FGAWR = 4050#, RGAWR = 4800#, GVWR = 8200#, CCC = 2286#, and the GCWR = 17,100#. The truck was rigged for towing, meaning all the normal tools, generators, gasoline, compressor, etc were on board as well as a full tank of gasoline.

My travel trailer is a new Jayco Jay Flight 23RB. It's a "stick and tin" built trailer and no slide. GAWR = 3500# each, GVWR = 6500#, Factory Shipped weight = 4758#, CCC = 1742#.

These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

[Atlee]

I did ask the manufacturer why my 27' 2" trailer with no slide has a GVWR of 6500# and the almost exact copy, except 2' longer than mine, but built the same and with no slide has a 7000# GVWR. I got an answer, but don't understand it.

This is the answer. "Because of the extra footage on that unit it ups the cargo carrying capacity of that unit your cargo carry capacity is 1940 that units is 2195 dimensions and weights are the difference."

atwowheelguy wrote:

Atlee wrote:
Thanks for all your help so far. Hope you don't mind me asking more questions. You are helping me understand all this stuff better.

I have another question. This is a more generic one, I'm afraid. Why would 3 different trailers that have the exact same tires, and exact same axles have 3 different GVWR?

Why would a 27' 2" long trailer with 3500# axles be only 6500# GVWR, while 28' 8" trailer (albeit with a slide) with the same axles equal 7500# GVWR, while a 29' 3" third trailer with the same axles equal 7000 GVWR.

Would the frame make that much difference? I'm sure the same springs are used on all three, since it's a lot cheaper to buy 3 copies of one spring set rather than 1 copy of 3 different spring sets that go on the same axles.

Also, all three trailers use the exact same size wheels and tires, ST205/75R15 LRD Goodyear Endurance tires.

You'll have to pose that question to the manufacturer''s engineers. Mine has a published tongue weight of 765 lbs and two 3500 lb axles. The GVWR is 7765, which seems logical to me.

[Atlee]

When pulling the trailer it will only be the two of us, or maybe our 5 year old granddaughter.

If we have more than that in the cab, we'll not have the trailer behind us.

atwowheelguy wrote:


But yes, a couple more passengers on board would put it at the limit.

[myredracer]

atwowheelguy wrote:

myredracer wrote:
I note besides all the above posts, the remaining available payload capacity of the truck is 220 lbs with it fully loaded for camping and the TT hooked up. The effect on the tongue wt. with partial or full holding tanks will depend on the location of the tanks. If you're going to do that much, perhaps a tongue scale would help. I think 220 lbs could be eaten up quickly if not keeping an eye on things.

Look again. The case with 220 lbs. payload remaining is WITHOUT the weight distribution bars attached. With the bars attached, the remaining payload of the truck is 340 lbs. The weight distribution hitch transfers 120 lbs. from the truck to the trailer axles. Or maybe it's 140 lbs. depending on which scale is correct. Anyway, the truck is 120 lbs. lighter and the trailer is 140 lbs. heavier with the WDH bars attached.

But yes, a couple more passengers on board would put it at the limit.

You are correct. I had thought about that and was going to include it but a day later forgot all about it. Not a good sign. 😞

[atwowheelguy]

myredracer wrote:
I note besides all the above posts, the remaining available payload capacity of the truck is 220 lbs with it fully loaded for camping and the TT hooked up. The effect on the tongue wt. with partial or full holding tanks will depend on the location of the tanks. If you're going to do that much, perhaps a tongue scale would help. I think 220 lbs could be eaten up quickly if not keeping an eye on things.

Look again. The case with 220 lbs. payload remaining is WITHOUT the weight distribution bars attached. With the bars attached, the remaining payload of the truck is 340 lbs. The weight distribution hitch transfers 120 lbs. from the truck to the trailer axles. Or maybe it's 140 lbs. depending on which scale is correct. Anyway, the truck is 120 lbs. lighter and the trailer is 140 lbs. heavier with the WDH bars attached.

But yes, a couple more passengers on board would put it at the limit.

[myredracer]

Atlee wrote:
Why would 3 different trailers that have the exact same tires, and exact same axles have 3 different GVWR?

Why would a 27' 2" long trailer with 3500# axles be only 6500# GVWR, while 28' 8" trailer (albeit with a slide) with the same axles equal 7500# GVWR, while a 29' 3" third trailer with the same axles equal 7000 GVWR.

Would the frame make that much difference?

I've wondered about that too. Doesn't seem to be any standard method for arriving at a GVWR figure. I don't think the frames have much of a bearing, if any. Some TTs have the very flimsy/flexible frame made with I-beams that have 3 pieces of mild steel welded together that look like a regular I-beam. I know of one brand/model with this frame and it has 2 @ 3500 lb axles and a 6800 lb GVWR. Our TT has a custom one-off heavy duty frame with 2 @ 5200 lb axles (and LRD tires) but the factory gave it only a 6800 lb GVWR (which it would normally have for this model) when it ought to be more like 9500 lb GVWR. They simply reduced the CCC to under 1K lbs to account for the heavier frame instead of assigning a new GVWR to it. TT GVWR is typically a few hundred lbs less than the sum of the axle ratings.

The thing about frames is, there are no industry regulations and standards and a TT manufacturer along with the frame manufacturer (mostly Lippert) can build them however they want. The frames themselves have no max. weight rating. If you go to an RV show and crawl under some TTs, you will find that for the same trailer having 2 @ 3500 lb axles, some Lippert frames are stronger than others and some can have reinforcement in the area of the spring hangers. And then there's the same GVWR but with the flimsy/flexible 3-piece I-beam frames. Best frames out there IMO are the ones made in-house by Northwood and the BAL Ultraframe.

Anyway, I note besides all the above posts, the remaining available payload capacity of the truck is 220 lbs with it fully loaded for camping and the TT hooked up. The effect on the tongue wt. with partial or full holding tanks will depend on the location of the tanks. If you're going to do that much, perhaps a tongue scale would help. I think 220 lbs could be eaten up quickly if not keeping an eye on things.

There is no restriction on how heavy TW can be in terms of percentage except you don't want to exceed payload capacity of the TV. In the US & Canada, the required resolution of scales is +/- 20 lbs. I once weighed our TT & TV on the same day at 3 different scales and were all within 20 lbs.

[atwowheelguy]

Atlee wrote:
Thanks for all your help so far. Hope you don't mind me asking more questions. You are helping me understand all this stuff better.

I have another question. This is a more generic one, I'm afraid. Why would 3 different trailers that have the exact same tires, and exact same axles have 3 different GVWR?

Why would a 27' 2" long trailer with 3500# axles be only 6500# GVWR, while 28' 8" trailer (albeit with a slide) with the same axles equal 7500# GVWR, while a 29' 3" third trailer with the same axles equal 7000 GVWR.

Would the frame make that much difference? I'm sure the same springs are used on all three, since it's a lot cheaper to buy 3 copies of one spring set rather than 1 copy of 3 different spring sets that go on the same axles.

Also, all three trailers use the exact same size wheels and tires, ST205/75R15 LRD Goodyear Endurance tires.

You'll have to pose that question to the manufacturer''s engineers. Mine has a published tongue weight of 765 lbs and two 3500 lb axles. The GVWR is 7765, which seems logical to me.

[Atlee]

Thanks for all your help so far. Hope you don't mind me asking more questions. You are helping me understand all this stuff better.

I have another question. This is a more generic one, I'm afraid. Why would 3 different trailers that have the exact same tires, and exact same axles have 3 different GVWR?

Why would a 27' 2" long trailer with 3500# axles be only 6500# GVWR, while 28' 8" trailer (albeit with a slide) with the same axles equal 7500# GVWR, while a 29' 3" third trailer with the same axles equal 7000 GVWR.

Would the frame make that much difference? I'm sure the same springs are used on all three, since it's a lot cheaper to buy 3 copies of one spring set rather than 1 copy of 3 different spring sets that go on the same axles.

Also, all three trailers use the exact same size wheels and tires, ST205/75R15 LRD Goodyear Endurance tires.

[atwowheelguy]

Atlee wrote:
Where did you get the 1100# max tongue weight from?

It was just a guess because it wasn't listed.
I have found that for some rigs, that's the first weight limit that's exceeded.

I have a 1000 lb. tongue wt. with a 1050 lb. limit, only 50 lbs. to spare.

Here's your data, complete. Put it in your glove box on the truck.

[Atlee]

Where did you get the 1100# max tongue weight from?

[Atlee]

A few answers.

Max tongue weight of the hitch w/o WDH is 500#. Max tongue load w/ WDH is 1,130#

I was hauling between 50 and 60 gallons. The trailer gauge for fresh water had just lit up 2/3 full. So I don't know exactly how many gallons I had. The fresh water capacity is 90 gallons including hot water heater.

Tires certainly aren't the limiting factor. They have a 2150# capacity, totaling 8600#. They are GY Endurance ST205/75R17 LRD.

Don't know about the tongue couple.

I bought the truck with HDPP. It was hard to find, and wouldn't have traded by old 2005 F150 on anything but a HDPP. This one was located up in PA by my local Richmond, VA dealer.

Besides the wife and I, I added a Leer cap on the 8' box, plus I carry an air compressor & 2.25 ton floor jack, plus 2 Honda 2K gennys, 13.5 gallons of gasoline, tools, etc in the bed.

I want to trim some weight off the tongue. Yesterday I did remove 71#. I weighted the removed items as I removed them from the front pass through storage. The pass through storage is about 6 feet behind the tongue couple.

I do know it towed well this past weekend. Very civilized. Didn't pay the passing 18 wheelers any mind.

[atwowheelguy]

Atlee wrote:
I just took another look at the numbers I put in the post. I did find two typo's. The line with WDH engaged, the Steer Axle should read 3580# (not 3520#) and the GCWR should read 13,320# (not 13,200#). Sorry for any confusion.

Atlee wrote:
Weighted my truck and trailer Friday, before we went on a weekend camping trip. The trailer is brand new. It had never been out camping before.

My WDH is the Blue OX Sway Pro. With 1k bars. I put it up to the 9th Chain link as called for in the book, and the Tech who installed the the Blue Ox
First, my TV is a 2014 F150 XLT 4x4, Supercab, 8 ft box, with Max Tow Package, and the HDPP. The FGAWR = 4050#, RGAWR = 4800#, GVWR = 8200#, CCC = 2286#, and the GCWR = 17,100#. The truck was rigged for towing, meaning all the normal tools, generators, gasoline, compressor, etc were on board as well as a full tank of gasoline.

My travel trailer is a new Jayco Jay Flight 23RB. It's a "stick and tin" built trailer and no slide. GAWR = 3500# each, GVWR = 6500#, Factory Shipped weight = 4758#, CCC = 1742#.

These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

Did you ever look at the sticker on the hitch receiver to determine the weight rating?

Some interesting things to see here.
WDH adjustment looks pretty good with 75% of the lifted weight returned to the steer axle.
Trailer 1742 payload but 1562 loaded on it. 180 capacity remaining. Were you hauling water? There's something other than the axles limiting the GVWR. Tongue coupler? Tires? I'm just curious.
Good thing it's a HDPP truck. 2286 payload, but 1086 loaded in it before attaching the trailer. 340 capacity remaining in the truck.
2648 lbs. of passengers and stuff in the truck and trailer.
15.5% of the trailer weight on the tongue.
Only 78% of the GCWR used up.
It looks pretty good to me. Happy towing!

[atwowheelguy]

jadatis wrote:
Then your trailer is exeption to the rule.
Exeptions make the rule.

I am not familiar with caravans in Holland. Perhaps the norm for rating caravan GVWR in Europe is different than the standard in the USA.

In the USA, travel trailer axles are usually rated for 3500, 4400, 5200, 6000, 7000 or 8000 pounds. They are usually furnished with tires rated for at least the axle load rating. Often the GVWR is the sum of the axle ratings plus the tongue weight.

[Atlee]

I just took another look at the numbers I put in the post. I did find two typo's. The line with WDH engaged, the Steer Axle should read 3580# (not 3520#) and the GCWR should read 13,320# (not 13,200#). Sorry for any confusion.

Atlee wrote:
Weighted my truck and trailer Friday, before we went on a weekend camping trip. The trailer is brand new. It had never been out camping before.

My WDH is the Blue OX Sway Pro. With 1k bars. I put it up to the 9th Chain link as called for in the book, and the Tech who installed the the Blue Ox
First, my TV is a 2014 F150 XLT 4x4, Supercab, 8 ft box, with Max Tow Package, and the HDPP. The FGAWR = 4050#, RGAWR = 4800#, GVWR = 8200#, CCC = 2286#, and the GCWR = 17,100#. The truck was rigged for towing, meaning all the normal tools, generators, gasoline, compressor, etc were on board as well as a full tank of gasoline.

My travel trailer is a new Jayco Jay Flight 23RB. It's a "stick and tin" built trailer and no slide. GAWR = 3500# each, GVWR = 6500#, Factory Shipped weight = 4758#, CCC = 1742#.

These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

[Atlee]

My trailer definitely has 2 3500# axles, which of course totals 7000#. The yellow sticker on the side of my trailer definitely shows 6500# as the GVWR.

jadatis wrote:
Reaction to above.

Also added up the WDH engaged 3 weights and so total weight must be typing error.
But this explanes the large difference of 100 lbs it gave between WDH engaged and disengaged, now its only 40 lbs difference, because of measuring differences of scale, and not 100.

GVWR is in rule always less then the GAWR's added up, and this is to allow some weightshifting between the axles.

For TV this means that you can still put some more load to front or back without overloading one of the axles, but in practice if loaded to GVWR, mostly rear axle is at its GAWR or even a bit overloaded, and front is way below GAWR, by the way you can load a car( space for load only at rear even behind rear axle, and towbar)

For tandem-axle Trailer, like you have, the hight of the towbar influences the weightdivision between the axles.
If your towbar is higher placed then average, it lifts up the front axle of trailer, so larger part of total weight on rear axle and front axle less, and the other way around.
Then if realy loaded Trailer to 6500 lbs, the weights on axles can be , 3500 lbs on rear axle and only 3000 on front axle.
Lower towbar is the other way around.

This differce in towbar hight happens when WDH engaged and disengaged, so if you would also have weighed the Trailer axles seperately, you would have notice next.
WDH disengaged> towbar lower> Loaddivision F+/R-.
WDH engaged > towbar higher> loaddivision F-/R+.

For axles only counts the total axle weight max allowed so GAWR,
but for pressure advice-advice you have to be ware.
Then even for that the crossed weightdivision between axles, is not important , only highest axle-end counts for setting the pressure, because rule is to give both sides on the axle the same presssure.