Towing Definitions-Understanding Towing weight terms

[cpaharley2008]

Cut and pasted from other websites
Understanding RV Weights
For the safety of your family and others around you, it is crucial to understand and stay within the weight ratings of your RV and tow vehicle.

Vehicle and trailer weight numbers fall into two categories:
Actual weights: Measured weight of the vehicle or its components. Factory quoted weights may be averages or estimates of actual weight.
Ratings: Weight ratings are limits placed on the vehicle or its components, which should never be exceeded.
DISCLAIMER: While we believe that all information on this web site is accurate, we can not guarantee that it is applicable to You specifically or to Your situation.

The most common confusion about weights occurs when the two above categories are mixed.

GVW: Gross Vehicle Weight Gross Vehicle Weight (GVW) is the actual weight of the fully loaded vehicle or trailer, including all cargo, fluids, passengers, and optional equipment, as measured by a scale.

If you are in a motor home and not towing anything, the GVW is the total weight of the RV and everything in it. If your RV is composed of more than one unit (towing a trailer or a vehicle), then the GVW is only part of the total.

The GVW is important because without this number you can not determine if you are within the limits set forth by the manufacturer, laws, and regulations. This number can be approximated based on information provided by the manufacturer or dealer, but the only way to be sure is to drive the RV on a scale and measure it.

GVWR: Gross Vehicle Weight Rating Gross Vehicle Weight Rating (GVWR) is the maximum number that the GVW or GTW should never exceed. GVWR is applied to trailers as well as vehicles, but you may see this rating referred to as the Maximum Loaded Trailer Weight.

GTW: Gross Trailer Weight Gross Trailer Weight (GTW) is the same as Gross Vehicle Weight (GVW) when referring to a trailer. While GVW can be applied to tow vehicles and trailers, GTW makes it clear that we are speaking of a trailer.

When connected, a portion of the trailer's weight is transferred to the tow vehicle through the hitch. In this case the GTW includes all axle GAW's and the Tongue Weight or King Pin Weight.

When not connected to the tow vehicle, the trailer's weight rests on its own tires and on all deployed support and stabilizing jacks. If you are weighing a trailer without the tow vehicle, be sure to place the entire unit on the scale, including all jacks.

GCW: Gross Combination Weight Gross Combination Weight (GCW) is the actual weight of the fully loaded tow vehicle plus the towed vehicle (trailer, car, boat, etc.), including all cargo, fluids, passengers, and optional equipment.

If your RV is composed of more than one unit (towing a trailer or a vehicle), then the GCW is the total weight of all connected vehicles and every thing in them.

Again, the only way to accurately determine the GCW is to drive the entire assembly on a scale. You may also determine the GCW by adding up the individual GVW's of all components.

If you weigh the components separately, make sure that they are configured and loaded exactly as you will be when traveling.

GCWR: Gross Combination Weight Rating Gross Combination Weight Rating (GCWR) is the maximum number that the tow vehicle GVW plus towed vehicle GVW (or GTW) should never exceed.

GAW: Gross Axle Weight Gross Axle Weight (GAW) is the actual weight placed on a single axle. Assuming a well-balanced vehicle, the GAW is then evenly distributed to all tires on that axle.

In addition to the axle weight rating, the GAW must be within the tire weight ratings as well. To determine the amount of weight placed on each tire, divide the GAW by the number of tires on the axle.

You may see the more specific RGAW, when referring to the rear axle, or FGAW, when referring to the front axle.

GAWR: Gross Axle Weight Rating Gross Axle Weight Rating (GAWR) is the maximum number that the GAW of a single axle should never exceed. You may see the more specific RGAWR, when referring to the rear axle, or FGAWR, when referring to the front axle.

Tongue Weight or King Pin Weight Tongue Weight (also called Tongue Load) is the actual weight pressing down on the hitch ball by the trailer. The recommended amount of Tongue Weight is 10-15% of the GTW.

King Pin Weight (also called Pin Weight) is the actual weight pressing down on the fifth wheel hitch by the trailer. The recommended amount of King Pin Weight is 15-25% of the GTW.

These weights are added to the tow vehicle's GVW.

Curb Weight Curb Weight is the actual weight of a vehicle or trailer including all standard equipment, full fuel tanks, full fresh water tanks, full propane bottles, and all other equipment fluids, but before taking on any persons or personal cargo.

We have seen the following variations to this definition:
Includes driver
Includes optional equipment
Pay close attention to how the manufacturer defines Curb Weight because this is often used to calculate other weights, such as the cargo carrying capacity or Payload.

Dry Weight

Dry Weight is the actual weight of a vehicle or trailer containing standard equipment without fuel, fluids, cargo, passengers, or optional equipment.

We have seen the following variations to this definition:
Includes commonly ordered optional equipment
Includes fluids of generator and other on board equipment (oil, coolant, fuel)
May or may not include RV batteries
Pay close attention to how the manufacturer defines Dry Weight because this is often used to calculate other weights, such as the cargo carrying capacity or Payload.

UVW: Unloaded Vehicle Weight

Unloaded Vehicle Weight (UVW) is the weight of a vehicle as manufactured at the factory. It includes full engine and generator fuel tanks and fluids, if applicable. It does not include cargo, water, propane, or dealer-installed accessories. Be aware that some manufacturers weigh each unit to determine UVW, while others provide only the average or estimated weight for each model.

We have seen the following variations to this definition:
Includes actual factory installed options
Includes commonly ordered factory installed options
Pay close attention to how the manufacturer defines UVW because this is often used to calculate other weights, such as the cargo carrying capacity or Payload.

Cargo Weight

Cargo Weight is the actual weight of all items added to the Curb Weight of the vehicle or trailer. This includes personal cargo, optional equipment, and Tongue or King Pin Weight.

This number is important because it will determine how many things you can safely pack into your RV. Within this number you need to fit the weight of your clothes, shoes, linens, books, dishes, beer, cleaning supplies, computer equipment, hiking gear, bicycles, water sport implements, food, beer—basically everything you want to take with you.

Payload Even though it does not include an R, Payload is a weight rating. It is the maximum weight that persons plus cargo should never exceed.

Payload is derived by subtracting Curb Weight from GVWR. In other words, the difference between a vehicle with standard equipment and the maximum allowed weight.

source of information http://www.airsafehitches.com

[rabbit]

Jim, the fruits of your labor of subjects of tires, weight and weighing should be made sticky.

jack

[Dave and Kathie]

Francesca Knowles always has this link in her signature - very informative!
Travel Trailer Weight Calculator

[cpaharley2008]

Originally Posted by rabbit

Jim, the fruits of your labor of subjects of tires, weight and weighing should be made sticky.

jack

do they not show as stickies?

[Borden]

We pull with a car much is the same GTW and GVW but no GCWR

> Car load limit that includes; people, pets, cargo, hitch, draw-bar, tongue weight listed on the inside door; this does not include the vehicle weight. (Legal limitation) this is why we travel with the trunk empty

> Tongue weight limits; experts told me that higher ground clearance of trucks is why the tongue is often listed as being set at 10% to 15% but cars are lower to ground and only require 8% (the higher the vehicle the higher the % recommended) but > MTO said it must ride level and be in control and not exceed the hitch limit (legal limitation)

> Trailer weight limits based on tire rating limit total for all tires and axle limits (legal limitation) *(needs brakes if over 3500 lbs.) your area may be different.

> Our car has an unbraked limit for towing due to braking limits of the car set by the manufacturer; this is not an actual legal requirement but a recommendation. (personally feel we should follow this for insurance purposes)

> Hitch limits (class I, class II, class III) (legal limitation)
(Minimum class II for our trailer as it is over the 2000 lb. limit of a class I, no class II made for our car so needed to spend on a class III frame hitch) was also recommended we use a WD system. Smaller trailers will not require WD but sway bar we had on the smaller trailer helped in wind.

> Braking rules for towing in *Ontario include a 50% rule; it the trailer is over 50% of the weight of the towing vehicle you need trailer brakes regardless of trailer size *(legal limitation)

> Tire limits on sidewalls; told by MTO we can use car, light truck tires *but sidewall limits reduced by 10% and not recommended also the tire expert and the RV dealer both said they would not recommend it.

> Breakaway switch *(required by law) on trailers with electric brakes by MTO (Ministry of Transportation of Ontario) may be different in your area

> Speed limitation ; the trailer must be level and in control at all times some areas have a trailer speed limit of 55 mph or 90 km/h (many exceed this and may be unaware of the limitation)

We have to use a little common sense past the laws. The TV must have enough horsepower and torque to do the job (a 76 hp tractor has an enough torque to pull more than we are ever likely to want to pull)

That is why some say 100 hp per 1600 lbs. but this is only a guide line as it makes no adjustment for gearing. We do not want to blow the transmission or transaxle and have to be able to clime the hills. For long hauls a transmission or transaxle cooler was recommended to us (dealer wanted it as well; warranty purposes)

I know it is not law but personally feel any load over 500 lbs. should be braked.

The WD draw system we have has a sway bar it helps in wind and keeps us level; down side is the extra weight added to the car load limit. We had a sway bar added to the old class I hitch for windy day with our smaller trailer.

*MTO Ministry of Transportation Ontario requirement

[Borden]

Wow long post: the legal part forgotten is in control would not pull our trailer with smaller car regardless of hp or gearing as trailer may take control; but this is only an opinion

What has always supprised me is the amount of miss information I am no expert but did talk to them before hitting the pavement.

We need people like cpaharley to help us understand the facts.

[ggillotti]

I bought a 13ft Surveyor camper trailer. I have a 2012 Colorado which in the manual says towing capcity 2400lbs. It looks like the Surveyor is 2700lbs. I'm new to this world. Looks like I need a bigger truck?

[cpaharley2008]

or a smaller trailer...

[Bob Miller]

Originally Posted by ggillotti

I bought a 13ft Surveyor camper trailer. I have a 2012 Colorado which in the manual says towing capcity 2400lbs. It looks like the Surveyor is 2700lbs. I'm new to this world. Looks like I need a bigger truck?

IS that 2700 lbs actual scale weight or a WAG????

I don't have a clue about what a Surveyor looks like, but a 13' FGRV that weighs that much would benefit from a season on "The Biggest Loser".

Tell us about your trailer.

[Bob Miller]

Thanks to Google I now know what a 13' Surveyor might look like.

It's a Forest River built sticky and, although I couldn't find one as small as a 13' on the web site, the slightly larger ones are, at least in FGRV terms, very heavy.

As in the case of FGRV's, I'd bet that you gain between 500-750 lbs. between mfg (empty) weight and your going-down-the-road actual weight and a trip to the scales is in order.

No matter what the outcome at the scales, it sounds like you need to find a better weight match between your TV and trailer.

BTW: Did a selling dealer tell you that you could tow the Surveyor with your Colorado?

[ggillotti]

Thanks Bob I appreciate your help. Not a dealer but a private seller convince me I could pulled it. Should have done research
Gary

[MC1]

Originally Posted by ggillotti

Thanks Bob I appreciate your help. Not a dealer but a private seller convince me I could pulled it. Should have done research
Gary

I guess it boils down to what criteria the private seller is using to come to that conclusion. True the tow rating is not the key factor in determining what a vehicle can tow safely and efficiently*. It is a complex subject. Lots of researching needs to be done.

*As many folks have found out. They bought a vehicle using only the tow rating as a guideline and found the vehicle was not capable of doing what they thought it should do.

[Bob Miller]

Ya.... But

When the trailers weight already exceeds the towing limit of the TV, it should be a no brainer.

But I recognize that those numbers are considered to be only a suggestion by some.... I would bet that the $eller was much more in $elling than in Safety.

[MC1]

A good point Bob. There is much confusion when it comes to tow rating/ tow capacity/ tow vehicle capabilities/etc, to list a few.

A good example of this would say a vehicles that is rated to tow say 2,500lbs.

But if the trailer has brakes then it is rated higher. Nothing about the TV has changed but an external condition (brakes are added to the trailer) has increased the rating of the TV.

[Bob Miller]

Quote: "But if the trailer has brakes then it is rated higher. Nothing about the TV has changed but an external condition (brakes are added to the trailer) has increased the rating of the TV."

Can't agree with that as a blanket statement. Some vehicles have separate ratings for towing with and without brakes but, unless that is specified, I don't see any way you can justify towing over the stated limit.

For that matter, as almost all trailers over 1500 lbs come with brakes, (as is required in many jurisdictions) raising a stated 2500 lb towing limit because one is towing a 3000 lb trailer with brakes, just begs the question.

Towing is as much about pulling and handling as it is about stopping.

[Francesca Knowles]

Originally Posted by MC1

A good example of this would say a vehicles that is rated to tow say 2,500lbs.

But if the trailer has brakes then it is rated higher. Nothing about the TV has changed but an external condition (brakes are added to the trailer) has increased the rating of the TV.

Perhaps you forgot the qualifier that this is only true within the limits imposed by the tow vehicle manufacturer. As Bob points out above, many/most give two tow limit numbers, which depend on whether there are brakes on the towed unit.

The vehicle is still limited to the maximum (braked trailer) weight stated by the manufacturer.

[Roger C H]

Here is a good website which covers all aspects of towing.

They talk about trucks and bigger RVs, but the same principles apply to our little rigs.

RV Safety & Education Foundation

[larrivee1]

Thanks all for tare ,net and gross ratings.The video from "Roger's site and RVSEF" was awesome !
happy travels

[floyd]

It is a real blessing that this is an electronic medium, if it were paper, this subject would cause major deforestation and then "WHO,WHO" would explain that to the Spotted Owl? (If one could still be "spotted")
Carry-On! This won't take much coal!

[C&G in FL]

Originally Posted by floyd

It is a real blessing that this is an electronic medium, if it were paper, this subject would cause major deforestation and then "WHO,WHO" would explain that to the Spotted Owl? (If one could still be "spotted")
Carry-On! This won't take much coal!

Now you've got me thinking Floyd. Is the bird in question called a Spotted Owl because it has spots, or because people frequently get a glimpse of one. Don't mean to introduce another species, but you've opened up a real can of (Earth) worms!


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