Tank size vs quantity pumped

[speedlever]

I often put in more fuel than the official size of my tank (even though I've never run this vehicle out of gas). Any estimate I use for the actually capacity will be a guess.

I've found that some gas stations have different pump flow rates that oftentimes shut off the flow prematurely leaving a tank not fully topped off. Other stations allow me to fine tune the flow and I get much more fuel in the tank before the shutoff actuates (without overflow or spillage). This is the occasion when I'm able to put more fuel in the tank than it officially holds.

Do you have any thoughts on how to accurately show the quantity of fuel?

Also, having just installed the UG, I found that with approximately 1/4 tank, I was able to zero the fuel quantity and show an add of 6 gallons which represents my best guess as to how much fuel actually remains in the tank at this point.

[Intruder1400]

SL,

First, you might check your actual tank specs online. Just to make sure. 

Second, show your gallons used on the UG.  When you fill up from a previous fill up, you can then see how accurate the UG is... there is a way to calibrate your UG, which I've already done and found the default UG settings to be under-reporting fuel usage by about .058 percent.  For relative accuracy use the same pump. You should also calibrate your miles.  Then you will be getting a accurate actual fuel usage.

[catnapped]

Seems like the only way to do that would be to know the 'actual' capacity of the tank versus what the written specification is.  I've also seen where filling past the first or second pump 'click-off' goes past whatever UG is interpreting as "full" and won't let me input the entire amount pumped.

[speedlever]

I think the best way to do this is via trial and error. The gas tank obviously holds more than the official quantity. I can normally pump in about 3.5 gallons additional after the first auto-shutoff of the fuel pump handle... depending on if the fuel pump allows me to finesse the flow or not. I rarely see fuel in the filler neck when I do this and only had one spill when I wasn't paying attention.

I changed the fuel quantity in my UG from the factory spec to what I think it should be based on my personal fueling habits (added 3.5 gallons to the official size). It will take a while to prove/disprove whether this works accurately. I need to do a calibration run too. My vehicle is MAP, not MAF. and I've enabled VE efficiency too.

[Intruder1400]

Be carefull about over filling your gas tank. Many newer vehicles have a charcoal canister as part of their EVAP system. If you over fill the gas tank, you may flood the canister and make it inoperative, resulting in your CEL (light) coming on. Replacing a charcoal canister ain't cheap.