I drove my NC2 from home up to Inverness which is 400 miles. The reserve light came on 20 miles from Inverness and the needle quickly hit the stop.
Started sweating a little as there are no petrol stations on that last stretch. Anyway arrived on the outskirts of Inverness and filled up. The car had 5 litres left in it having driven for 20 with the reserve on so should be good for at least 50 miles on reserve assuming normal fuel consumption I would say.
I donāt like to run right down to zero as I was brought up that the dregs will be full of rubbish, dirt, rust etc that will spoil your fuel system.
That uphill thing is horribly familiar.
In my case on the M25, hoping to get to the Shell station just off J18. The road rises and falls gently. First sputtering started on an uphill bit, then over the crest it was suddenly fine again and my hopes rose, but I could see the road ahead also gently rose toward the exit and I knew I was doomed. Conked out and coasted to a halt on the side of the slip road.
Martin Young,
Ditto my mk 2.5 
I know it well, worked in Rickmansworth for about 6 years.
Wow 420 miles is good going.
I thought so as well
Iād brimmed the tank before leaving and wasnāt racing mainly driving at 60-70mph. The last few miles on the A9 were a bit stressful as there were no fuel stops that I saw or maybe I ignored them I canāt quite remember. I do remember there were lots of up and down gradients all with the needle hard on the stop. Actually it was fine there was over a gallon left in the tank assuming it was petrol and not water or other rubbish. So I reckon 50 miles is easily achievable when the reserve light flicks on.
Yes, all one needs to do is remember the mileage when it first came onā¦
Zero the trip??
Hmm, at first sight a good idea, but after thinking about it for a minute, too complicated!
And I do use the trip, so would be losing data.
Remembering is part of keeping properly awake, and allows more attention to be on the road instead of looking for how many button presses, after finding it, etc
There are two trip counters on the ND - not to say you donāt already use them both for other purposes!
Two on the NC too if I remember correctly (such a long time since I drove it) A+B trip .