First, anyone who tries to squeeze the last mile out of a tank of gas before stopping to fill up is just asking for a little exercise as he walks to his destination, or a little wait after he calls his auto club.
Very sound advice. So many factors affect the mileage at any given time. Are you in the city, on the highway, is it windy, is the bike loaded down with gear, are you running it harder than normal?
I ran out of gas on my softail, heavy wind, little lady on the back, gear loaded down. Light came on, I knew that I have about 32-35 miles to hit a gas station......first time I road under all those conditions at once......passed 3 exits with no highway gas station.....near huntsville, TX (state prison for the bad boys)....coasted to the curb in 104F heat (Girlfriend was 210F Boiling Hot).
Got lucky and was picked up by a highway service patrol on my walk to the service station - took only 20 minutes to get enough fuel to make it to the next station (girlfriend was a bitching 210F by then) - never run it that low again, nor trust any gauge on a Harley.
I noticed on my CVO with that little mileage gauge, that estimated milage will jump all over the place unless your cruising at a very consistent speed - immediately set the counter to my current mileage on that tank.