WAHOO! 50.0 mpg, 10 tank average in 28y/o Honda Civic...
...done with hypermiling driving techniques and pumped up tires. No special aerodynamic modes.
My daily work commute is 72 miles roundtrip.
I EOC on my 2 minute drive to the freeway, because a cold engine uses a lotta fuel.
Because I leave before the crush of the morning commute traffic, I'm able to maintain a constant 53mph speed in the slow lane.
I exit the freeway 3 miles short of my destination, so I can take advantage of EOCing in such early morning hours on empty city streets.
Unfortunately, with the return leg home there's no way to avoid the commute traffic.
Being a competitive sailor, I have observational skills of watching water current as to make the quickest passage over the race course. As I would observe the flow of a river, I observe freeway traffic the same. I have learned to the shift lanes to best avoid areas of more congestion, such as merging traffic from another freeway. In bumper-to-bumper, slow traffic, I leave enough space between me and the car ahead so I VERY rarely step on my brakes.
Why 53mph? The faster you go above 55mph degrades your MPG exponentially. 53mph is close enough to 55mph, whereas other drivers will believe I am actually driving 55mph and that either their speedometer, mine, or both are off just a tiny bit. There's less chance of road rage towards me, if other drivers believe I am doing 55mph.
53mph takes me 5 minutes longer to drive to work.
This 50.0 was accomplished with a stock, 1989 Honda Civic hatchback; no special aerodynamic treatments. Tires pumped to their maximum pressure, though. Anyone can do it. Just be observant and patient.
Brilliant. Today I managed a trip of 80.2 miles on a mix of highway, town/city streets and country roads at 63.3 UK mpg (52.7 US mpg) in my Honda Jazz. I do not use EOC and my tyres are set for the max indicated on the door pillar sticker (Honda's recommendations).
I pretty much follow the same techniques as you do.
2006 Honda Jazz 1.2i-DSi S Vivid Blue Pearl