I’m not here to teach people to suck eggs. However, I have managed 500 miles to a tank. I have a 22 miles A1/Motorwayish/highway road for the Americans to my place of work. 1 mile out to the A1 and 1 mile to my office from the A1.
I have managed 500 miles in my MK7 GTD at the hideous price of fuel. I have been trailing lorries in adaptive cruise control. I find it be best at level 3 on the distance thingy, as there is less heavy braking and accelerating when the lorries hit inclines etc. Too close and you’re slowing and accelerating too quickly.
Everyone says that eco mode is pointless. (I agree somewhat). I find that eco mode is not really about economy, it’s is more about adjusting your driving style to not drive as intensely. In eco mode, the throttle and everything is very slow and dulled down as you know. This is great for driving like a granny. Which when I use adaptive Cruise Control it is great. I have found to get another 75-100 miles per tank by trailing behind lorries. This is the only time in my life where lorries haven’t pissed me off.
Average behind a lorry is 62-65mpg (UK mpg).
If anyone has any further advice please let me know - I would use vegetable oil, but my car is too new haha!