Community Forums

JDT · 05-07-2010, 05:14 PM

My real question is how much diesel will a 100 gallon Monaco fuel tank hold?

Okay, now that you've had a good laugh, I have a reason for asking. I have always assumed my 100 gallon tank on my Ambassador held more than that when I filled it to the brim. Now that I am using a VMSpc one of the features I really like is the miles to empty and gallons left info. It seems it would be more accurate if a fill up was, say, 105 gallons, instead of the 100 gallons I have it programmed for now. Now does my question make sense? Hope so.

itdave · 05-07-2010, 05:26 PM

I would be surprised if it you can get 100 in the 100 gal tank. On my 06 Endeavor I can only get in about 80 to 90 gal. Monaco positioned the fill spout below the top of the tank, so there is no way you can completely fill the tank. Depending on the angle of the MH when filling determines how close to full you can get. On my Aladdin I generally set the fuel level to 80 gal and plan on refilling when I get down to 25 gals remaining. Others may have different info.

RVRon · 05-08-2010, 07:44 AM

Working capacity of a fuel tank is usually 85% of stated capacity. Then, like ITDave said, your fill pipe position counts and then there is the question of where your individual pickup tube is positioned in the tank. I look for fuel at just below half tank. I have more peace of mind that way.....

bborc · 05-08-2010, 01:45 PM

I have a 07 Knight with the 100 gal tank. I had to drain the tank and pull it out for a leak around the drain plug. When I refilled it I had the MH level and measured every drop I put in it. It took 100 gal to bring it up right to the lip of the filler tube. I measured the tank while I had it out and it can hold 110 gals. but the filler tubes are at the 100 gal level so you have about 10 gals of empty space above them. Also I figured it takes about 6 gal to bring the level up 1 inch in the tank. So as you can see if the MH is leaning just a little towards the side you are filling on you could be less than 100 gal but if you were tillted the other way you could go over the 100 gals. Hope this helps.

JFC · 05-08-2010, 03:39 PM

My 2002 Ambassador had a stated cpacity of 75 gallons of fuel. I was stupid enough to run it completely out of fuel. Coach died on the apron of a fuel station. Bought two gallons of fuel, started the coach and drove into station. Took 58 gallons to fill the tank with an automotive, slow fill nozzle.

JDT · 05-08-2010, 07:21 PM

Thanks for the responses to a not so logical question. When I filled up yesterday after our trip to Branson, it took 40.3 gallons to fill it to within about a half inch of the lip of the filler tube. Using the 100 gallon setting on my VMSpc trip minder, which I reset at the start of the trip, it showed I had 55.3 gallons left. My fuel guage showed a little more than 1/2. Adding the 40 made it 95.6 which I know is more of a close estimate. Guess it is best to leave it at the 100 right now or maybe adjust it down to 95 to leave myself a cushion.

DtBt · 05-12-2010, 03:03 PM

You can also adjust correction factors for fuel usage within vmspc. In your case the ECM thought it used 44.7 gallons when you actually used 40.3 gallons. To correct for this a fuel correction factor would be 0.9 instead of the default 1.0. Of course you should do several fill ups to and average results.

Bobs911 · 05-15-2010, 08:59 PM

I went through a similar exercise determining what a safe reserve would be in my 75 gal tank. I was expecting to be able to use 65 of the 75 safely. After calculating how many gallons per inch were in my tank, there was no way I was going to run around with less than 3 inches of fuel. It would only take a slightly unlevel situation to suck air. Now I plan my useable at 55 gal.