Fill to fill pump shutoff strategies for consistency

[R.W.Dale]

I have been always getting a lot of variability I feel in my MPG calculations more than I suspect the car is actually generating.

Recently and this never occurred to me that there's apparently some strategies to how you set a pump and let it shut off.

I try to use the same pump. I click it to the highest flow notch and let it click and hang it up..

One method I read about was letting the pump run till it clicks, wait 30 seconds and fuel to the next cut off.

What are your thoughts and what methods if any do you use to get the most consistent results at the pump?

Thanks

[freebeard]

I use second click. If the tank doesn't vent, first click is unreliable.

Someone serious about this will T into the fuel line and add a one gallon calibrated auxiliary tank, and then run on the regular tank until the transmission is warmed up.

[aerohead]

I set it to the 'slowest' setting.
When it clicks off I insert a 6-inch stainless-steel thermometer stem down the filler neck to hold the detent door open.
I dispense the fuel until it clicks off.
Keep repeating until it won't take any more.
Then lift the nozzle out until I can see past it, then dispense until the fuel rises to a 'ringed rolled edge inside the neck, and just sits there.
Completely full.
I can read and record the fuel temperature at the same time.
--------------------------------------------------------------------------------------
This probably violates every manufacturer recommendation, regarding protection of the emissions controls.
I've never experienced any engine trouble, but I can't recommend it for anyone else.
--------------------------------------------------------------------------------------
Every fuel tank has a captured-air space above the fuel, when 'full' to allow for thermal expansion.
By setting the flow rate to the minimum, it's an attempt to not overwhelm this captured air volume, by some surge caused by 'fast' filling.
-------------------------------------------------------------------------------------
During fueling in Seymour, Texas on one trip, it required 16-'clicks' before the tank was actually full. A descrepancy of 1.6-gallons between an 'indicated full' and an '
actual full.' A 6.66% difference. Which has extreme ramifications when 'looking' for an mpg change-due-to-modification.

[R.W.Dale]

I employed a strategy based on the advice given and by the mpg calculation and looking at the gauge the tank accepted significantly more fuel.

Knowing I needed 4 plus gallons I let the pump rip for the first two gallons then I locked it on the lowest notch until it clicked, waited several seconds and eased fuel in until the second shut off.

We'll see if overall this leads to more consistent results

Thanks all

[redpoint5]

I don't bother because the long-term average is what I'm after. A 1-tank fill doesn't tell me much about anything in particular, even if my fillup was super accurate.

[Mcgiiver]

Originally Posted by redpoint5

I don't bother because the long-term average is what I'm after. A 1-tank fill doesn't tell me much about anything in particular, even if my fillup was super accurate.

Here in New Jersey , we are not allowed to pump our own gas, so we are at the mercy of the pump morons. Since most do not speak English, I gave up trying to reason with them and just look at the long term average.