Proper fill-up?

[monroe74]

Originally Posted by cems70

The gas log you see is for my '95 Civic DX hatchback, not my former '95 VX

Oops, my mistake. Thanks for pointing that out.

Originally Posted by Jay2TheRescue

Because if you overfill the tank the vapor recovery system on the fuel pump will suck up the excess gasoline

That's been my experience, too. But he claims that he was being careful to make sure the vapor-recovery holes (near the tip of the nozzle) were never submerged. Also he says that his overall mpg was consistent with the gas actually entering the tank. So I think these factors turn the situation into a mystery.

[Jay2TheRescue]

LOL, my old AMC Spirit did that... It was a tiny hatchback with either a 21 or 25 gallon tank. I don't remember now. It would click off the first time when there were about 15 gallons in the tank. If you clicked the pump back on you would usually get another 5 gallons in at least, and this was before vapor recovery, so everything did go in the tank. It was funny to be with grandma when she put gas in the car. It would click off and grandma would yell "Keep Pumpin'!" The attendant would usually respond with something to the effect of "Its a little car lady.", but sure enough you could get several more gallons in after it clicked the first time. I remember it was nothing to get 700 or 800 miles to a tank in that car.

-Jay

[Ford Man]

I think the reason for getting several more gallons of fuel in the tank after the pump shuts off is because the car manufacturer measures the tank capacity to where the tank float stops and on some cars that is a few inches from the top of the tank plus the amount that you get into the filler neck. My '88 Escort has a 13 gallon tank but I have put slightly over 14 gallons in it before and wasn't completely out of gas when I did it, because I drove the car into the gas station. The 14 gallon fill up was topping off the tank. I can usually get between 1 and 1 1/2 gallons in after the pump first kicks off. I also remember that the gas gauge was a little below empty when I put the 14 gallons in it.

[thornburg]

Yeah, the other responses are headed in the right direction with this: Your fuel tank is basically 'rated' for a certain capacity -- this is not actually a measure of how much it holds, but of how much they expect it to take before the pump shuts off, and is the "recommended" fill capacity. The tank will hold a little more, plus the filler neck, and some vehicles (such as VW TDIs) have a "vent" that can be used to let pressure out of the tank and fill more easily (and in TDIs, this mechanism could be removed to even further increase the capacity--google "ventectomy"--note that this could apply to all VWs, I wouldn't know, as I have never owned a gas-powered VW).

Despite all these various other places that fuel can go, I don't believe you generally should exceed your tank's rated capacity.

If you are about to hop on the highway and drive 500 miles, then it might be worth it, but, personally, I don't think it is worth the potential of extra wear & tear, spillage, etc in regular daily driving.

[joeventura]

Stop pumping when the handle clicks?
I have had an empty tank and the handle clicks after half a gallon.

And its not practical to say use the same pump at the same station, that's good in an ideal world where you never have to drive anywhere further than half the distance of a full tank.

The method I use is quite simple, look into the filler port while pumping, the first time you see gas (i.e. it bubble up to the top) then stop.

Don't round to the dime or the dollar, when you see the gas, you are full.

[theholycow]

Originally Posted by joeventura

And its not practical to say use the same pump at the same station, that's good in an ideal world where you never have to drive anywhere further than half the distance of a full tank.

Well, it's not THAT rare; it's just that it's most useful to say in the context of repeatable experiments. I commute the same way every day, and I do get gas on the same side of the same pump every single time. In the last three months or so, I have had to wait for that pump once. Every other time I just roll right up to it. Obviously it's more difficult for people in busier areas or people not on the same route.

[99metro]

Originally Posted by joeventura

Stop pumping when the handle clicks?
I have had an empty tank and the handle clicks after half a gallon.

And its not practical to say use the same pump at the same station, that's good in an ideal world where you never have to drive anywhere further than half the distance of a full tank.

The method I use is quite simple, look into the filler port while pumping, the first time you see gas (i.e. it bubble up to the top) then stop.

Don't round to the dime or the dollar, when you see the gas, you are full.

Sorta agree with this. My diesel might click off 3 or 4 times depending on how dirty their filter is, what angle I have the fill nozzle, and much pressure the pump has (if there a more than one person pumping from the same tank, the flow/pressure drops). Sometimes I am clicking off .2 gal a second, and sometimes I'm clicking off .05 gal a second. Something to take note of. This WILL affect where the pump auto stops.

So, MY thoughts are to pump at a consistant flow till the autoshutoff, then one more click to ensure it's not a premature stop. Pick something you can be consistant at, like .1 gal a second or .2 gal a second. The very very very accurate way to ensure a full tank is to keep filling until you get spillage (but I wouldn't do this in practice! - nor recommend it). Unless you see the gas through the hole, you can be off by as much as a gallon to a gallon and a half before actually being full.

In summary, do the same thing every time and be consistant.

and that in my opinion is that

[palemelanesian]

Has anyone tried using a dipstick to check the fill level?

[R.I.D.E.]

I like it, a dipstick for your gas tank.

Actually I was thinking about a drip feed tank that would connect to the filler neck. Make a separate fitting into the filler neck about 4 inches from the top, and connect it to a separate tank which would drip feed gas into the main tank when the level dropped below your tube.

Then you could weight the test tank before and after for precise fuel consumption.

regards
gary

[R.I.D.E.]

Actually you could use a piece of clear tubing and a golf tee. mark the tubing at the point where you want it to be at the top of the filler neck, stick it in the neck and stick the tee in the end of the tube. Pull the tube up to see where the fuel level is located. Make the tube long enough so it will stay under the fuel level as you check it.

regards
gary