Hi,
I can see you guys want to get the most miles out of your tanks of diesel and feel somewhat aggrieved when there is still fuel in the tank however diesel engines are not like petrol. If you run out if diesel you have to bleed the system to get any air bubbles out (fine if you have the mechanical know how and time) whereas in petrol engines you can just fill up, turn it over A few times and it should be okay.
My personal view is look at the bigger picture, you probably shouldn't worry about that last 20 odd miles as it’s probably saved you time and money getting your car fixed and some untold damage which are exasperated on older cars like ours. This is also the reason manufacturers build in a margin of safety (it probably helps reduce warranty claims too).
Separate but related note, I wouldn't even consider running out of fuel on my FSI since it’s direct injection, I’m running it with mechanical sympathy in mind. The only A2 then that I’d happy run out of is the 1.4 petrol but really what’s the point? Just calculate what you had left in the tank and multiply by your current mpg, then add to the miles that you’ve done for a theoretical maximum.
I’m also one for hyper miling But not at the expense of other mechanical costs. Just my opinion so please don’t shoot me down.
Jeetesh