The light come on kind of early for my liking as well. The Fuel Capacity is 6.6 Galllons. If you are usually putting in about 4 gallons......there would still be 2.6 gallons, enough for about 80 - 100 miles. (but what is the point passing gas stations when you only have 2 gallons in the tank) You might as well fill the tank and empty the bladderMine seems to come on early as well. I wish I knew exactly how much was left when the light comes on, or that the gauge was more accurate. If you have two gallons left in like what.....a 5 gallon tank, that is not really low fuel.