I have an 08 Electra Glide classic. I believe it has a 6 gallon fuel tank. When it is on empty, I fill it and I can only get 4 gallons in. So is there 2 gallons left after empty? I know the manual says that when it gets low enough a "low fuel light" will come on. I have never seen this light even though I have ran it right up to the big E. I wouldn't know what the light looked like if it did come on? Does it say: "low Fuel"? I just want to know for sure when I absolutely need fuel.