This was only my 3rd fill-up but it was a convenient way to calibrate the gas gauge. The 1st beep and flash of the bottom bar happened just as I arrived home. The next day I drove 3 miles to the gas station at about 74 mpg so that didn't take much gas. The fill-up was 9.33 gallons so there was about 1.5 gallons left good for at least 50 to 75 miles. The Trip Miles to Go said 22 miles so now I know what the "safety factor" is. In addition it confirms that 1 Bar approximately equals 1 gallon. (I had pretty much the same calibration 1 for 1 at a half tank.)
Yes, I use the 1 bar = 1 gallon approximation. It is not exactly linear but a good approximation. I know that at 1/2 tank that if I divide the miles driven by 5 gallons it comes fairly close to the displayed mpg minus the +5-6% error.
