I had it happen to me the other day. I had two bars and I had already riden about 150 miles, so I knew it was about time. I figured that I could hit up a gas station a little bit down the road and I didn't make it. I had to sit on the side until someone stopped to help. It was a little embarrassing, but also pissed me off. I kept waiting for the little blinking light to yell, "Hey idiot, get some gas!!!" But, it never did. Now, I will keep track with my odometer and always fill up around 140-145.