So the other day I was driving the lovely S to autocross. It had a little less than a quarter of a tank left of fuel according to the gauge on the instrument panel. All of the sudden (about 5 min later) the fuel light comes on. Shortly after that all the bars on the gauge are not lit showing me on empty. So I turned into a gas station and filled the gas tank up with 12 gallons fuel and it has a 13.2 gallon tank. Anyone else have this issue? I know the fuel light comes on when you have about 2-3 gallons left. Just wondering why there was such a quick jump from a quarter to empty.

 

Did you warm up the vehicle. How many bars did u have

 

The gauge samples the level sending unit and averages the reading over time. Auto-X sloshes the fuel all over the tank and as a result, the level sending unit sends these changes. The gage reads these changes and averages the reading you see, it is also delayed.

 

Below 1/4 of a tank, I've noticed the fuel gauge drops like a rock - and this is in normal driving. I would imagine with autocross it's even worse. Cruising on the highway it literally only takes me 15 miles to go from 1/4 of a tank to empty.

 

Ok thanks for the help. And yes, I always let the car warm up to atleast three bars before putting the car into gear. This happened on the highway about 10 minutes after starting the car while driving on the highway. Im glad to hear Im not the only way that has experienced this. I had about one or two under a 1/4 of a tank.