When I began my fuel saving adventure, I posted this thread mistakenly under 'Success Stories' - sorry, I was new here - but it seems that it is turning out quite well. In the meantime I cracked the code to get my car below 3l/100km, as I did a roundtrip yesterday with an endresult of 81.1 MPG or 2.9l/100. To me, it is a greater achievement than the previous one-way trip @ 84 MPG. Because this was a tour, starting and ending at the same place. And also because the average speed was a bit higher.
Result: 81.1 MPG or 2.9L/100km
Distance: 73 miles
Average speed: 49 MPH
Weather: sunny 24°C, 5 MPH wind from different directions
Road profile: 90% highway, slightly hilly
As a bonus I filled the tank and found out it was the best one ever. See my fuel log to follow it up.