358 miles from fill up full to fuel light coming on, on way back from the 'ring this weekend in the MK3 roadster. Very happy with that!
I get 33mpg driving sensibly in my 1.6 mk1 or 30 thrashing it. I love how far you can drive after the fuel gauge needle has come to a halt at the bottom of the gauge! I’m stating to wonder if I can teach it to run on fresh air 
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That’s a very interesting statement that you make about how low can you go. I was intrigued by this when I got my Eunos 1.6 in 2008 so I ran the car until the needle aligned with the ‘E’ mark and then removed the fuel pump from the top of the tank. I was amazed to see just under 2 gallons of fuel left in the tank. The issue that gives this effective ‘under-reading’ is the crank angle on the sender unit arm. I emptied the tank and added exactly 1 gallon, then adjusted the sender arm crank. Now ‘E’ on my gauge equates to half a gallon. Having done that and carefully filling to 10 gallons, thus proving the gauge and the adjusted volume, I get an accurate return of upto 39.7 mpg. Don’t forget, a properly balanced exhaust and a high flow induction kit makes a difference too.
If you dare, keep a gallon in the boot and run it dry. Don’t worry too much about dirt in the tank, there is a super fine gauze mesh on the filter so you cannot suck up any dirt. Put exactly 1 gallon in and see where your needle goes to.
We have averaged 41 mpg over the last 4,000 miles of mixed driving.
Longest before re-filling the tank with 48 litres was just over 400 miles - since the needle was below empty I decided we had pushed it far enough.
I believe it is a 50 litre/11 gallon tank, so a little further should be possible 
I bet it wouldn’t move with how far I drove. I did approximately 45 miles after the needle hit E and I didn’t wait till it stopped. Unless I’m on the way to work running out is no big deal, my other halfs favorite game is petrol station bingo so I’m no stranger to having to walk to the nearest station after breaking down lol. For your entertainment, next time I get to empty I’ll reset the trip and see how far I can get