Originally Posted by stevehnm
Do you mean when the gauge reads half tank it doesn't fill up to half the spec'd volume or what? What are you basing this on? Fuel gauge, tank fill vs. mileage, dash gauge, Scangauge (or similar) or what?
On page 124 I described exactly what is still being questioned. (Which has been answered a couple of more times since.) A simple float is what has been used for many years. It used to be brass float soldered onto an steel arm. Nothing magic. It measures the level
of fuel in the tank, not the volume. On older cars, tanks were typically square, rectangular, etc. Not complex shapes to fit around suspension or anything, so it was pretty consistant. That has changed over the years, but a float is still a float. Like I said before, if a pyramid was the shape of your tank the level would drop quickly near the top and slow down as you worked your way to the bottom, (volume). If the pyramid was upside down, the level would drop slowly at the top and much quicker toward the bottom. A float is a simple device. Like I said, don't confuse level and volume.
As for the dash puter, it does not calculate based on the float level. It uses the puter and bases its readings on fuel flow, extrapolating injector pulse, air temp, engine temp, rpm, etc. It is giving you numbers based on engine management parameters.