I have an 09 R56 base that I've owned for a little a year. Since I have bought it I have had an issue with the gauge reading that the tank has less fuel in it that what it really has. For example tonight and went an bought some gas and put 13.4 gallons of gas in it. After I started my car it showed that I was three clicks away from being full, but I know that's impossible since I just put 13 gallons into it. I have no idea what to do. The last time I looked up a fuel pump it was around $500 for a fuel pump. I'm not sure if I should just learn to deal with it or if I should start saving up a "million" dollars to fix this.

 

The foam float on the fuel quantity sending unit on the LPFP canister can become fuel soaked over time and will cause exactly what your describing.
Found it for $112 shipped from here: Link

 

It's not the fuel pump, it's probably what Tigger said. As long as the gauge doesn't say you have gas when you run out you're OK. Right?

 

Thanks guys. I know that I've wanted to change the fuel filter so now I can add on doing the float. I found a local shop that specializes in BMWs and MINI not that far from me in Noblesville Indiana. All of his guys are BMW certified. Now it's time for the fun part, saving up the money to pay for a new float and the filter.