After owning my car for more than six months now.. I finally realized that I always have some diesel fuel behind the fuel filler door and I could see the trace of diesel coming out from the filler hole between it and the cap.

One day I decided to buy a new cap...

It didn't make any difference at first except for stopping the leak. However lately I am starting to notice that my fuel gauge works even when the fuel level is less than 1/4 (it didn't work before or would work once in a blue moon)

Any ideas why it would make such a difference? or is it something I put in the fuel that cleans the sensor or something?

Just something that I still can't quite figure and might help someone out there...

__________________
2008 BMW 335i Coupe