Highest Miles to Empty at Fillup

What's the point of figuring out that. I thought Prius people are looking forward to fill up, you don't get many chance for doing that.

 

Sounds like you might be running the tank awfully low up to 610 miles. 610 / 56 = 10.9 gal.

1 gallon (if that) left in tank doesn't leave much for fuel pump. Don't want to starve fuel pump.

It's fine to fill up at 1 or 2 pips left also. I usually do.

 

When car manufacturers give fuel tank gallon capacity, do they measure just the tank or does that include the filler tube as well ? Most cars this does not matter but in the Prius, an extra quart or two in the filler tube could make a difference of 15 to 30 miles more. This could come handy if you can't find an open gas station.

 

That's true about the fuel pump not getting cooled. It's always better to fill up around a 1/4 tank and up. I was also of the understanding that running the gas level really low could cause small particles from the gas tank to clog the fuel injectors... :noidea:

 

Fuel to empty is calculated by considering the recent consumption and the amount of fuel in the tank as calculated by the amount used since fill up. If you are driving in a low consumption environment your miles to empty will be high but if you then go into a high consumption environment your miles to empty will fall rapidly, this applies in the opposite situation too.

The fuel consumption is calculated by knowing the flow rate of the injectors and the amount of time the injectors are opened for each mile. Fuel injectors open for one to four milliseconds, that is 1 to 4 thousandths of a second each revolution IF fuel is injected at all. This is a very clever system and considering the frequency and short duration of injection, very accurate. I should also say this isn't just used on Toyota but all modern vehicles with consumption readout. In the old days actual fuel flow was measured but that was when carburetors were still in use.