Tank Capacity

[RJ82much]

Hi all,

I took some crude ruler measurements of my freshwater & holding tanks plus did some comparisons against online replacement tanks. I do not know who made the tanks for GSC.

The freshwater tank measures approximately 7 3/4 inches high & 17 1/2 inches wide. It extends about 2 ft less than the 100" total width of the coach. Unlike the GSC claim of 70 gallons capacity, I calculate a maximum possible of 55 gallons; more than likely as little as 48 gallons.

The grey & black water tanks are difficult to ruler measure. Curbside height of each is 4 1/2 inches & width is 18 1/2 inches. Note that this end should be raised off the deck (or hung flush with the overhead floor) by approximately 2 inches so that fluids will flow toward the drivers side. The driver's side of each tank is most likely a little over 6 inches in height. I'm estimating the maximum length of each tank to be under 60 inches. Replacement tanks of those dimensions are rated at about 25 gallons - a far cry from the GSC claim of 50 gallons.

In summary, by MY estimate:
a) freshwater = 50 gallons
b) greywater = 25 gallons
c) blackwater = 25 gallons

[ronbo]

Hi Bob -

A man after my own heart. I too want to know DEFINITIVELY what I have, and not what some shiny prochure advertises or implies. You kept at it longer than I did, I gave up after the first wacko-reading I'd made.

Mfgr's usually include the water heater when boasting of their capacities. As far as black/waste water capacities, maybe they include the amount when everything backs up into the commode, sink, shower, etc? (yucko!)

You might be able to weigh the capacities by going to a Love's, Flying-J, or similar that has an rv-section and a scale. Weigh it one way and then fill (or empty) the appropriate tanks and then weigh it again. All other things being equal, you should come out pretty close.

Thanks!
Ron

[RJ82much]

Good point - I did forget the water heater, which I think is 12 gallons?

Weighing would be an accurate means, so long as the scale is sensitive enough to see a couple pounds difference. Are they? and, can you get enough time at a Flying J scale to do that kind of experimentation? Do you have to pay each time you get a weight? (As you can tell, I've never done it)

[GStream40]

One way to check any tank appox. capacity is to take a garden hose and fill a 5 gallon bucket while watching your watch as to how long it takes to fill the bucket.

Then run the hose into the coach and fill your tank in question while watching how long it takes to fill the tank completely, not by the level gauge, but actually is full enough to fill to the drain so that it won't go down. Watch the shower/tub drain as it will back up there before a sink drain will.

Take this time, divide by the time it took to fill the 5 gallon bucket, then multiply times 5 = the amount of gallon size of your tank.

This method should be close to the size of your tank in your coach.

If you don't want to do this, then fill a 5 gallon bucket and dump down your drain and repeat this until tank is full. Count the amount of buckets and multiply times 5 to get your tank capacity.

Oh, BTW I believe all RV water heaters are either 6 gallon or 10 gallon in size. These are the size tanks that Gulf Stream uses. Also some manufacturers include the hot water tank size in the figures for the fresh water capacity. I am not sure if Gulf Stream does this or not but according to my test figures on my coach they do not.

Many storage tanks in our coaches are made with "steps" and are not the same size all the way across, I know my fresh water storage tank is. It is made to go almost all the way to the top of the compartment on the passenger side but it is made to slide under the frame rail on the drivers side. It is 90 gallon in size, believe me, I checked. :D

Also, the black and gray are 75 gallon each, once again I checked them with the above hose method. The figures came out within just a couple of gallons each.

Ron

[lockdoc]

Oh, BTW I believe all RV water heaters are either 6 gallon or 10 gallon in size. These are the size tanks that Gulf Stream uses. Also some manufacturers include the hot water tank size in the figures for the fresh water capacity. I am not sure if Gulf Stream does this or not but according to my test figures on my coach they do not.



Ron

Ron-
Not to be picky but the new GS lines do have a 12 gallon HW heater in them.....at least per their owners info and brochures.

[GStream40]

Hey, That's great, 2 more gallons to take a longer shower with. :)

Ron

[Retird2Golf]

:P Now you guys got me getting out the old tape measure............

:twisted: And I thought I just p**d a lot .... :idea:

[oubruceb]

I used a 5 gallon bucket and measured how much water I got out of my shower. My factory brochure says my Prairie Schooner has a 60 gallon fresh water capacity. 3 times I came up with 34 gallons of fresh water before my pump ran dry. I filled it all 3 times till it ran out, let it sit , then tried to add more. 34 gallons is all it held. My dealer also checked this and found the same thing. With the bottom off we measured the tank and it should have held 42 gallons (outside measurement). I called the factory and the person I spoke to said they include the hot water tank. There is always a note on all brochures that specs can change. I bought my trailer new in 2003, I would have hoped the factory would have changed their advertising to reflect a closer measurement of true capacity. I dry camp and one of the reasons I chose Gulfstream was the large tanks. The factory has been very good in fixing all of my other concerns, but on this one I was told 'tuff'.