My poor spreadsheet

Like many others - I've tracked all the gas I have been putting into my 2006 Prius for several reasons. First of all, in an effort to do a manual mileage calculation to compare with the MFD readout. Secondly, by tracking each tank from a know starting point, I can make some assumptions as to how much gas is in the tank before and after I fill up.

I use this two ways - I know there's 10.2 gallons in there as I just pumped it in, but can calculate I should have 1.1 gallons left in there from the last tank, for a total approximate tank of 11.3 gal.
Also, if I know there's 2.5 gallons left, I won't try to squeeze 10 more in, cause I'll get burped at. If I know there's 0.25 gal in there, (and the pump clicks off at 9.2), I have a good guess as to how much more I can try to squeeze in there.

Works for me (but then again, I'm a geek)

But there's just no way to account well for the past month. I filled up my car (just till it clicked) one day, drove it 100 miles (lost a pip), and then got into an accident. Car was hauled away on a flatbed, and repaired for 4 weeks.

When I got it back, the tank was registered full (10-pips), and had been driven 20 more miles. (So, topped off after 20 miles drive, I can sorta account for that). But while driving it, it became obvious something was wrong. Instantaneous mileage was reading correctly, but tank mileage was reading 7 or 8 mpgish.


This can only mean one thing - they accidentally ran it dry, at least twice. Someone failed to turn it off, and it cycled the ice on and off until the tank was empty. (At least twice). So now we have 20 gallons consumed, for 20 miles driven - 1mpg. Crap...

While giving the car a good workout after getting it back, I drove that tank till it flashed. Tank should now be near empty. So I filled it, and decided to top it up as much as possible. I put it a gallon after clickoff, and it took it. So I put in another gallon, and it took it. It seems I had the nozzle in there just right (wrong) as to plug the air sensors with the rubber gasket that force a shutoff, and it just kept pumping, and pumping, and pumping. I turned it off 3 gallons later, quite confused as to how I had just pumped 14 gallons into a 11.9 gallon tank.

(Everyone here knows what comes next)

I removed the nozzle, and the car burped, belched, and vomited the excess out. I had overfilled that bladder like a balloon, and with the nozzle removed, it squeezed the excess right back out. (And it was NOT a small amount, it just kept gurgling gas out for at least 60 seconds.

Excessively silly question: Could you do what I just did - over inflate the bladder by two or more gallons. And then when it starts glugging - grab the cap and screw it on to seal the exit? Would it seal tightly enough? Could you contain 14 gallons of usable gas in there by hand? Hmmm....

So - now I have a gas receipt for 14.3 gallons - but of course I don't have 14.3 gallons in my tank. So I guess I have to assume I now have 11.9, the generally accepted max for the tank. And I can think of no way for accurately 'adjusting' my worksheet for these two hiccups, so I may just start over. I'll only be throwing out about 4 fillups worth of data anyway...

-Ken