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GCWR and GVWR

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We are looking at a 2005 ITASCA Suncruiser 35A. The Gross Combination Weight Rating is 26,000, and the Gross Vehicle Weight Rating is 22,000. The fresh water is 92 gal., holding tanks 51/77gal., LP tank 28 and fuel is 75 gal. How much weight do I have to play with before the RV is overweight?

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Guest BillAdams

I had an earlier incorrect post here. I confused the information requested. Here is the correct one:

You need to have your coach weighed to see what it weighs now. You can use a truck stop weigh scale (under $10 I believe) for that number but you also need to know how much weight is on each tire so you can see if that load is balance properly and what pressure to use in your tires. Some weigh stations will allow you to move forward and back as well as side to side (2 tires on at a time) and you can do some math. The best way is to find an RV weighing service such as RVSEF (much more than just weighing, but they do offer this service) and drive up onto the individual scales. You will receive good numbers and a report on what is and what is not. They are at all of the major FMCA and Good Sam rallies as well as many others. If you Google them you will likely find if one of their teams will be in your area.

I recommend getting weighed with your fuel, fresh water and propane full and the other holding tanks empty as this will be an accurate measure of your traveling weight. With this information you should get a pretty good idea as to whether you can tow a 3500 pound canyon.

Be sure to add a braking system to your tow vehicle as well as properly rated tow bars and chains.

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GVWR is the Gross Vehicle Weight Rating. When the motor home weighs this much, you will be at full capacity. One more pound and you are overweight! This limit is related to the tires, brakes, suspension system, chassis design, etc. Exceed this weight limit and something will be damaged and eventually break. It then becomes a very serious safety concern.

You now need to know the Unloaded Vehicle Weight which includes full fuel, oil and coolant but does not include fresh water, propane or waste tank fluids. Once you have this figure you can add up the weights for the propane (6 lbs per gallon), water (7 pounds per gallon - works for waste tanks also) and then subtract the difference between the unloaded vehicle weight plus the above additions from the GVWR. This is the weight of the driver, passengers, clothes, computers, cameras, golf clubs, food, dishes, tools, lawn chairs, BBQ, etc. you will be able to carry.

The GCWR is the Gross Combined Weight Rating. It is the combined weight of the motorhome and any towed vehicle or trailer. The answer to the 2005 Canyon question lies in the difference between the GVWR and the GCWR. Given your figures above, the Canyon (fully loaded as you travel with it and fueled) can weigh only 4000 pounds. Check the owners documentation for the Suncruiser for information about the hitch rating. The hitch must be rated for 4000 pounds also.

As I indicated, the missing figure you have to find is the Unloaded Vehicle Weight. Our motor home has a sheet which gives all these weights. It is on the back side of one of the lavatory cabinet doors. I don't know where you will find it on your motor home but it should be there as I think all manufacturers were listing these values on a posting somewhere in the motor home for at least the last ten years. Read the sheet carefully and do a little math and you'll have your answers.

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OK, you have heard two good (and accurate) methods of determining what you can carry/tow.

Tom's method will likely be more realistic when considering a coach that is for sale, as some dealers are reluctant to allow you to take the coach off the lot to be weighted.

But, clearly, Bill's method (obtain ACTUAL weights) is more accurate. And should you buy it, will be high on the priority list.

Let me throw in a couple of more "gotcha's":

The reading of the coach weights from the sticker as Tom indicated may or may not be accurate. Some manufacturers post weights based on base coaches with options, even mandatory options sometimes not included in unloaded coach weight. And, clearly it will not tell you if one axle or wheel position is already at it capacity (i.e. the coach's weight distribution is poorly laid out).

The other issue is that it is very unlikely that you can use a coach's total GVWR, as to do that, weights would have to be balanced perfectly left/right and each axle loaded to its capacity. VERY unlikely. When any wheel position's weight is at 1/2 axle capacity rating, THAT IS IT for that wheel position. So, for example, you may have the front right wheel loaded to its carrying capacity, but because storage placement, may not be able to shift weight to the left. Or the whole front axle may be at weight limit with, perhaps 1000 pounds capacity on the rear axle, but no storage behind the rear axle to allow you to put your stuff here. This is especially true of coaches with tag axles, as the tag is normally where much of the CCC is, but no way to put your stuff in the very back of the coach.

Brett Wolfe

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GVWR is the Gross Vehicle Weight Rating. When the motor home weighs this much, you will be at full capacity. One more pound and you are overweight! This limit is related to the tires, brakes, suspension system, chassis design, etc. Exceed this weight limit and something will be damaged and eventually break. It then becomes a very serious safety concern.

You now need to know the Unloaded Vehicle Weight which includes full fuel, oil and coolant but does not include fresh water, propane or waste tank fluids. Once you have this figure you can add up the weights for the propane (6 lbs per gallon), water (7 pounds per gallon - works for waste tanks also) and then subtract the difference between the unloaded vehicle weight plus the above additions from the GVWR. This is the weight of the driver, passengers, clothes, computers, cameras, golf clubs, food, dishes, tools, lawn chairs, BBQ, etc. you will be able to carry.

The GCWR is the Gross Combined Weight Rating. It is the combined weight of the motorhome and any towed vehicle or trailer. The answer to the 2005 Canyon question lies in the difference between the GVWR and the GCWR. Given your figures above, the Canyon (fully loaded as you travel with it and fueled) can weigh only 4000 pounds. Check the owners documentation for the Suncruiser for information about the hitch rating. The hitch must be rated for 4000 pounds also.

As I indicated, the missing figure you have to find is the Unloaded Vehicle Weight. Our motor home has a sheet which gives all these weights. It is on the back side of one of the lavatory cabinet doors. I don't know where you will find it on your motor home but it should be there as I think all manufacturers were listing these values on a posting somewhere in the motor home for at least the last ten years. Read the sheet carefully and do a little math and you'll have your answers.

Correct weights: LPG is 4.2 lbs/gal & water is 8.3lbs /gal. Quite a difference if you're talking several hundred gals.

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Guest BillAdams
Correct weights: LPG is 4.2 lbs/gal & water is 8.3lbs /gal. Quite a difference if you're talking several hundred gals.

Diesel weighs about 7.3 lbs/gal. and gasoline about 6.2 lbs/gal.

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