The HB toy tank math problem


Ok, I initially thought that using toy tanks on houseboats was pretty straightforward...apparently that's not the case because everyone I talk to seems to have a different interpretation of how they work. And my personal experience with ours has been a bit of a mystery. I need help with the math and logic from you who are more experienced to make sense of this. With no DR, the gas budgeting stakes are much higher these days. Here is the fact pattern:

700 gallon total gas capacity on our HB
470 gallon advertised toy tank
only one gas gauge at the helm
2 ski boats (65 gal capacity each)
2 waverunners (17 gal capacity each)
All vessels are full of fuel from Page gas stations at the start of the trip

SImple Question #1: Is the toy tank and the tank for the HB motors/generators the same physical tank?

Simple Question #2: Do I have unconditional access to 470 gallons of gas in the toy tank that the HB motor/generators can't and won't touch?

Mysterious Question #3: How in the world do you make sense of what happened the last two seasons on 6 day trips???
Using the toy tanks, we filled up each ski boat 3 times, we filled up each waverunner 4 times, we drove the HB to Rock Creek and back from APM, we ran one generator approx 75% of the time, the gas gauge in HB showed completely empty when we got back to APM, and yet APM gave me a receipt for 550 gallons of gas to fill the HB back up at the end of the trip (we were billed 580 total gallons the previous year so it has been consistent)?????

How does this happen with a 700 gallon total fuel capacity? How did we use 500 gallons of the toy tank yet we supposedly only used about 50 gallons to drive the HB to Rock Creek and back and to run the HB generator for a week. Scratching my head.

[BTW...this is obviously not a cost effective trip going through that much fuel and it will be extra painful this year--thankfully it is spread over several families]

Anyway, it seems like we have overused the toy tank capacity (which I thought was limited yet we never ran out), underused the motor/generator capacity, and have been duped by a single HB gas gauge that I can't make any sense of. If we truly use 550 of a 700 gallon total capacity, the HB gas gauge certainly shouldn't be on empty or very close to it.

Can anyone help me out with how these tanks work and how this math works? I hate guessing each year and leaving things up to chance.

Michael Pyle

Active Member
Different Houseboats are plummed in different ways. So its really hard to know what your setup is unless someone has the same model and year. Which I didn’t see you mention in the post what houseboat you have.

We have two 380gallon tanks that both engines, Gen, and toy pump can pull from. There are manual valves we can move to make anything pull from either tank.

We know we have 380 each because measured them and calculated the volume. The dash gauges are not very accurate. We made a stick to check what the level is, which was easy because we have rectangle tanks with the fill at the top above the tank. The stick does not lie.

So you may need to do some research on your boat or find someone with the same model. But I would measure the tanks and not take anyones word for it.

We were told we had 2 400 gallon tanks but really was a little less.

Cruise speed effects HB fuel mileage a lot. Pulling back a few miles an hour can make a big difference.

Also we try and shut the Gen off during the day. Which cuts the fuel in half for a trip on the gen. But we have solar to run fridges, lights, AV, etc.. those solar panels will pay for themselves this year for sure. .



Active Member
We have a similar situation with a tank for the port engine, a tank for the starboard engine, a tank for the generator, and a "toy" tank. We are plumbed to draw from either the toy tank or the generator tank to our gas pump for toys


Well-Known Member
Each houseboat is plumbed differently. Ours with Laketime has 3 tanks. We can switch between the generator and engine tanks quite easily. The toy tank get used up every year filling up the ski boat and 2 jet skis. The generator barely hits 3/4 and the engines usually go to 1/2 a tank. We usually go to rock creek and don’t have an issue with needing gas. We also learned to drive the houseboat at below 3,000 rpm’s. Saves a lot of gas and not much speed is lost.