Unless riding at very steady speeds on a level road, such as a highway, the range display will always bounce around. In my opinion, your range was not 15 and 8, it was simply 8 'cause you should always use the lowest reading displayed over several seconds. And any reading, especially when in low gears and / or accelerating, under (or maybe even at) 10 miles or less is getting very risky IMO and IME.
Running out of fuel is hard on the fuel pump by the way. The fuel is also used to cool the pump motor as well as function as the bearing lubricant so running it dry starves the fuel pump of both. The good news is that there are quite a few used fuel pumps around now for C-14's as they are fairly expensive new.
Just a thought but if you really want to stretch the range as far as possible very often, you may want to consider carrying a small container of aux. fuel on the bike; there are liter or so bottles that fit neatly into a carrying tube mounted under a saddlebag. Now a liter (or a quart) of fuel is worse than useless if traveling on an Interstate in, say, Montana (it just makes the bear chasing you run further and more cranky before catching up with you the second time.....) but is more than enough fuel to get you to a fuel station in more densely populated areas, such as the northeast.... we almost cannot swing a dead cat around without hitting a gas station.
Brian
P.S.: No cats, dead or otherwise, were harmed during the typing of this message.
I ran out of gas (last night )!
I was riding home last night and RAN OUT OF GAS ! I was 1 mile from my local gas station (2 miles from home)! I had 220 on the trip for that current tank and my RANGE was showing 15 miles left. In the blink-of-an-eye my RANGE went from 15 to 8 and there she went...dry! I was riding in regular mode (rode the entire tank in REGULAR mode, not switched to ECONOMY mode) and got 220 out of the tank. 220 is good for keeping her in normal mode so I'm happy about that and I DO have Steve's flash :great:. I thought for sure I'd make it that 1 additional mile but nope...she wasn't going to get me there. Part of the problem was that I have a small grade I have to climb to get into "Oak View" where the Shell station is and as soon as I hit the grade it died...DEAD!
I called my wife and asked her to get a gas can, fill it at the Shell station and come help me. She had to travel 1 mile to the gas station (which was on the way to me...I'm talking immediately off the highway where I was) and then she had to drive 1 more mile to get to me...SHE TOOK 40 MINUTES ...she's so fired!
I will continue to ride in NORMAL Mode and know that I need to start looking at 200 miles knowing I have a 15ish mile cushion.