I noticed it yesterday when I filled up my tank. Before the fill-up, the needle is at the low red line and low fuel indicator is on. But it only filled about 12.3 gallons. The tank is designed to hold 15.8 gallons. I have made an appointment with the dealer. They said that they will take a look at it. Is my S40's fuel gauge faulty or they are designed this way? There are 3.5 gallon left in the tank when low fuel indicator is on and fuel needle is at the red line. Does anybody have the same experience?