Oil Math for Old Guy

[BillM2]

I filled an empty 275 gallon oil tank in late October with 175 gallons of heating oil. That amount did not fill the tank completely, obviously. Then, a couple of days ago, I added 200 gallons and it filled the tank to the very top. How many gallons did I use over 41 days? According to my questionable math skills, I burned about 100 gallons so my guess is 2.4 gallons during the period, but am I correct?

[jeff520]

2.44 gallons per day. You are correct.

[beenthere]

Is that the very top. As in the oil was touching the tappings at the top of the tank. Or that the fill gauge read full?

That can be a difference of 9 to 13 gallons.

[BillM2]

Very top of the tank. Delivery guy stopped when the whistle stopped.

Sdaly, the old red gauge is shot -- the float's saturated -- I'm going to replace when close to empty. The new ones don't seem to have the same gradual readings, however.

[beenthere]

Very top of the tank. Delivery guy stopped when the whistle stopped.

Sdaly, the old red gauge is shot -- the float's saturated -- I'm going to replace when close to empty. The new ones don't seem to have the same gradual readings, however.

If the whistle isn't cut shorter then from factory. Then you had several inches before the very top(I use to deliver oil, and installed a lot of 275 gallon tanks back in the 70s and 80s).

So your tank had at best, 260 gallons when he was done filling it, since oil does foam some while filling the tank.

So you could have used 120 gallons, or a bit more. Depending how fast he was putting the oil in.

When he fills it next time. You will have a much better idea of how much you really used.

As it is now. You could have used more then 3 gallons a day.

[BillM2]

When I bang on the tank it's totally solid. Even tapping on top it's solid. Does that tell me anything?

Also, are there more detailed, graduated gauges out there than the ones commonly sold at home improvement stores?

[beenthere]

Tapping/banging on the top of the tank won't tell you how full or empty it is.

I believe that there are still some gauges made that are calibrated in gallons. haven't tried to get one in a long long time though. So not sure.

[skippedover]

For a house that's getting 'automatic deliveries', the oil company attempts to deliver between 180 and 190 gallons to be most efficient. Anything over 200-gallons normally requires the driver to establish that the heat is on in the house and that the tank didn't run dry.

As beenthere stated, there is a whistle in the tank. That whistle has a long shaft, through which the air that is pushed out of the tank during filling passes, thus blowing the whistle. When the oil covers the shaft, the whistle stops blowing, indicating to the driver that it's time to stop filling the tank. The space at the top of the tank allows oil that's cold from outdoors to expand in the warmer environment of the basement.

It is interesting to note that the heat content of the oil delivered is somewhat lower than the heat content when it expands in your tank. In the truck, the oil is more dense and in your tank it is less dense. For a true reading of heat content, we would have to change the way fuel is delivered (same for gasoline) from gallons to pounds or weight. That way the temperature/density of the fuel does not matter, only the weight of the fuel. That is why jet airplanes use weight, not gallons, to measure fuel quantity.