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 > Actual federal weight law rules, some questions and answers

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Posted: 06/20/14 11:07am Link  |  Quote  |  Print  |  Notify Moderator

The lbs column is calculated at 700lbs per rim inch X 2 (Industry standard)

7.5 R 16.0 LT - 7.5 - 10,500lbs
8.75 R 16.5 LT - 8.75 - 12,250
9.5 R 16.5 LT - 9.5 - 13,300

LT 225/75R 16 - 8.8582677 - 12,402lbs
LT 245/75 R 16 - 9.6456693 - 13,504
LT 215/85 R 16 - 8.4645669 - 11,850
LT 235/85 R 16 - 9.2519685 - 12,953
215/75 R 17.5 - 8.4645669 - 11,850
225/70 R 19.5 - 8.8582677 - 12,402
245/70 R 19.5 - 9.6456693 - 13,504
265/70 R 19.5 - 10.433070 - 14,606
255/70 R 22.5 - 10.039370 - 14,055
245/70 R 22.5 - 9.6456693 - 13,504
265/75 R 22.5 - 10.433070 - 14,606
295/75 R 22.5 - 11.614173 - 16,260
295/80 R 22.5 - 11.614173 - 16,260
285/75 R 24.5 - 11.220472 - 15,709



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Posted: 06/20/14 11:20am Link  |  Quote  |  Print  |  Notify Moderator

ShapeShifter wrote:

blt2ski wrote:

If you understand the real laws as they pertain to how much wt you can put on an axel, you would know that

Obviously, I don't know the real laws, or I wouldn't be asking the question! [emoticon]

I've picked up some bits and pieces, but have trouble putting it all together. This thread has been very interesting, but also contains quite a bit of confusing and conflicting information. I have a tough time staying withing the manufacturer axle weight ratings on my rig (especially the 20k rear.) I understand the physical ramifications of that, but worry about the potential legal issues.

blt2ski wrote:

not over 500 lbs per inch width of tire, which is typically 10-12K per axel, you will not get an overwt ticket.

Great summary, thanks! Please double check my math: My tires are 275/80R22.5, which should give me a 275 mm tread width if I understand tire specifications properly. That's a tad over 10.8" per tire. At 500 lbs per inch, I figure that's 5,400 lbs per tire, or 21,600 for the axle.

So I take it my legal limit is 21,600 on the rear axle, and I'm within my limit. But the legal limit on my front axle would only be 10,800 on the front, even though the front GAWR is 13,000 pounds. According to my last weigh slip, my actual front axle weight is 12,240. So I was worried all this time about my rear axle, when it turns out the front is my problem? Yikes! [emoticon]

So I guess I need wider tires on my front? I don't think I have room for 315's, but that's what it sounds like I need... [emoticon]

transamz9 wrote:

Floats are the big wide tires that you see on the front of a lot of dump trucks and heavy haul semis.

Thanks! I was guessing something along these lines, but you know what happens when you guess and make assumptions, especially about trade jargon. [emoticon]

In many states the legal limit on steer axle is 20,000lbs and tire size is not even considered unless applying for an Overweight/Over dimensional permit. Only then is tire size considered.

So essentially, you could run around all day WITHOUT an OW/OD permit at 20,000lbs on your steer with only 7.5 inch tires and be legal, but once you obtain an OW/OD permit you are illegal.

This is a great example of how complicated weight/dimension laws are.
Additionally, there is Federal Bridge Formula that must be abided by in some states but not others.

In KY:
Max legal steer axle and single axle = 20,000lbs
Max tandem axle = 24,000lbs
Max triaxle = 48,000lbs

No carriers GROSS (truck, trailer, load) may exceed the plated weight of the TV unless the TV is licensed for 80,000lbs and an OW/OD permit has been obtained.


Buffalo, NY

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Posted: 06/20/14 01:13pm Link  |  Quote  |  Print  |  Notify Moderator

sacmarata wrote:

No carriers GROSS (truck, trailer, load) may exceed the plated weight of the TV unless the TV is licensed for 80,000lbs and an OW/OD permit has been obtained.

Thanks for the good info! You make me feel much less worried.

A clarification please, for someone who is not sure of all of the jargon/terms, but is making an assumption based on other discussion in this thread. But you know what happens when one makes assumptions...

When you say "plated weight" I assume you mean license plates - the weight that the vehicle is registered for (and which determines the registration fee.) You do not mean the weights on the vehicle manufacturer's rating plate (GVWR, GAWR, etc.) Correct?

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Posted: 06/20/14 02:35pm Link  |  Quote  |  Print  |  Notify Moderator

Correct. Plated weight = licensed weight.
Your gross weight may never exceed your plated weight.
This is the biggest violation for carriers under 26,000lbs that I personally know of and for every 10 that get caught 100 get away.


Kirkland, Wa


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Posted: 06/20/14 06:36pm Link  |  Quote  |  Print  |  Notify Moderator

Something needs to be pointed out here, SOME states allow up to 20K per axel no matter the tire width. Here in Wa st where I am, if you have singles on the rear, you get 500 lbs, if duals, 600 lbs. 10.8 x 600 = 6480 per tire or 12960 total.

here you RA would be a max of 20K, width total over 20K does not matter.

ALSO, as noted, plate PAID for wt is the important factor. My 2000 C2500 has an 8K plate, I can not legally per say go down the road at 8600 on the door tag, UNLESS, I bought a 10K plate, we buy in 20K increments at about 10-15 per ton, THEN I would be legal to 10K, door tag be dammed! My IHC dumptruck has a 26K plate, even tho door tag which is in office by the way, says 18200. My dually was licensed at 14K.

Another issue that may or may not effect some, HERE in wa st, one buys a min tag of 1.5 times the tare. If you truck comes in empty at 7K, typical say CC 4x4 SW rig with a manufacture plate of 8600-9900. You will have to buy a 12K plate, and you WILL be legal to 12K. A 7K x 1.5 is 10500, next higher ton is 12K.

The only state I know of that uses Rim width for max per tire per say is Indiana, and they give you 800 lbs per rim inch last I checked a decade or so ago...........

One does have to know HOW the individual states you run thru use and enforce the FBLs from a legal licensing stand point.


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Calgary, Alberta

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Posted: 04/23/15 03:45pm Link  |  Quote  |  Print  |  Notify Moderator


Good questions. My understanding is that AAM rates my rear axle at 10,800#s. GM then rates the axle down to 6084#s which is the tire rating total for the two stock tires on the rear axle.

this /\

and then this below...


I know that here in TX the state codes say that a load on an axle can not exceed the combined tire rating for the tires on said axle. I have 265E's which have a rating a little of over 3400#s each. That would limit me to a little over 6800#'s. I am currently under that by about 1300#'s.

I believe that the above two quotes brings us to the Tires...regardless what your axle is rated at...that information is meaningless unless you have tires rate ABOVE that rating...which aint gonna happen.

Logic dictates that if you load up an axles to say 8500 lbs and then blow a tire because you exceeded the tire manufacturers rating - and cause an accident - YOU are liable...regardless of the axle rating

My truck has 17" 265/70R17 BFG Rugged Trails

As per= jmramiiler states both him and I are maxed out at ~6800 lbs on the axle/tires. This at the maximaum rated pressure of said tires which is 80 lbs..I do believe that figure will drop as the tire pressure drops.

I live in Calgary Alberta. There is little enforcement of anything like this in our Province..and to be fair there is little anywhere in Canada...but as Noted previously, if your rig looks unsafe, thats when you are going to get pulled over...and from what I have heard from speaking with others, they will in fact go with the door sticker information if you are told to go a scale.

For me, I am likely OK as far as looking good, I added a set of Roadmaster Active suspension springs and it improved the stance of the truck when hooked up. But I am also pretty certain that although my rear axle weight is under the tire rating, I am over my total truck about 350lbs - All to do with pin weight.

I'm Ok with that..its just the beer.!



M'self and the Bride...of 32 yrs
'06 GMC DMax CCSB 594,545 km (368,890 miles)
2003 Citation 26RKS.



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Posted: 09/09/15 10:05am Link  |  Quote  |  Print  |  Notify Moderator

wow some reading.
my GM 1500 came with p rated tires and the plate showed rear axle at 3950
I have replaced tires with Mich 10 ply rated at about 3000 each. have installed air bags.
I see everyone says don't exceed axle ratings, but when adding better tires does it increase axle rating.

was the 3950 rating for the stock P rated tire?

what would the rating be from AAM be for my truck. .

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Tallahassee Fl.

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Posted: 09/11/15 12:46pm Link  |  Quote  |  Print  |  Notify Moderator

The tires are sometimes the lowest rated part that determines the GAWR but not always. The axle housing/bearings, springs, wheels, and frame also come into play. The most important is tires and wheels because the axle it self is usually rated much higher than the rest. Also air bags will help the springs rating. Find out what axle you have and then it's easy to look its rating up on Google.

Here are a few different ones that are common.

Dana 30 2,770 lbs Dana Corp.
Dana 35 2,770 lbs Dana Corp.
Dana 44 3,500 lbs Dana Corp.
Dana 50 5,000 lbs Dana Corp.
Dana 60 6,500 lbs Dana Corp.
Dana S 60 7,000 lbs Dana Corp.
Dana 70 10,000 lbs Dana Corp.
Dana 80 12,000 lbs Dana Corp.
Dana S 110 14,706 lbs Dana Corp.
Ford 9-inch 3,600 lbs Ford Motor Company
Ford 8.8 axle 3,800 lbs Visteon
Sterling 10.5 9,750 lbs Visteon
10.5 14 Bolt 8,600 lbs American Axle
11.5 AAM 10,000 lbs American Axle
10.5 AAM 9,000 lbs American Axle
Saginaw 9.5 6,000 lbs American Axle

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Posted: 12/21/15 09:57am Link  |  Quote  |  Print  |  Notify Moderator

SO does this mean that if you exceeded the GVW which is much
lower now that your liable in a accident because you were over
weight? The feds have forced manufacturers to reduce the
size of the holding tanks. Especially troubling is the fresh
water tank. Many of the new tanks only hold 30gals much to low
for our purposes as we stop at parks with only electric hookup
most of the time. Five gallons of water is no easy thing to
carry around or haul to a campsite. I'm glad we were thorough
before we bought a new RV with small holding tanks, sales people
do not volunteer this information.



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Posted: 12/21/15 04:53pm Link  |  Quote  |  Print  |  Notify Moderator

Travelnman wher do you get this from ? The Feds have forced manufactures to reduce the sise of tanks ? Was this a salesman ?

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