[Christ]

Proof for second click:

When the pump clicks, it's because fluid has re-entered the nozzle, changing the pressure required to flow the fluid into the tank. If it continues pumping after it's clicked the first time, it wasn't full. It will always stop at/near the entry point of the nozzle, within a few pennies' worth of fuel.

The remaining variable is nozzle depth. Most people just shove it in there to the hilt (LOL), so that's not really a variable either, since it's controlled as precisely as is easily possible.

Variances in vehicle angle, if subtle, will again, only mean pennies, if even that much. The filler neck is always the highest point in the tank, and as long as you didn't leave a massive air bubble in the tank because of an off-kilter angle, the variance in fills will only be the volume necessary to fill a small section of the throat near the fill nozzle.

Same thing goes for pump selection, because, again, they're setup to shut off when the pressure across the nozzle changes. For the same reasons as above, the variance in the filler neck will only be pennies.

For all those reasons, I just don't even pay much attention to where I fill up anymore, or how I do it. My variances are within a few tenths of a MPG normally, except when I start using my vehicle as more than a commuter, or making long trips. Then you'll see huge variances of several MPG (up to 10 at times) in my logs.

I haven't even been keeping the logs the way I should on Cara because of these types of tank variances, I've been doing alot of hauling of heavy stone and other materials w/ Cara.