Hi 2Sun, I have the 1800c with the 4.5 gallon tank. When I would run out of gas (on purpose), the tank would only take about 3.5 gallons too. So IMO the light is coming on at about the "normal" time, but your miles per gallon of gas seems very low (mid twenties mpg). As Spike said the mileage does improve with added mileage. When I had about 1,000 miles on the bike I was getting about 32 mpg, by the time the bike turned 2,500 miles, I was getting between 36 - 40 mpg. Twisting the throttle hard will take a toll on your mileage. Also, a bunch of people fill the bike when it is not leaning over, to get more gas into the tank. I complained to Honda, but they said it was normal. Finally, I did the mod to lower the fuel pick up in the tank, but it didn't help that much. Instead of having about a gallon left in the tank when it was out of gas, now there is about 0.7 gallon left. It didn't change when the idiot light comes on, just can go a little further (10 - 15 miles).