The total capacity is 21l with a 6l reserve.
There is no fuel tap or reserve switch... you have the gauge/warning lamp to tell you you're on the last 6l and that's it!
The last bar doesn't go away, it just flashes...ask me how I know.......
Luckily that bit of the M5 is downhill & I ran out about half way along the slip road to the services.....
