Piwoslaw, I have a lot of respect of your achievements and I assume they are based on technological readings of various reliable sources BUT how come my all time best fuel consumption with my diesel car are all done in summer on tanks where I tend to drive on the fast / non FE side (83 mph on the speedo or city traffic and A/C most of the time) - (more complaining time from the kids or more fuel, not one second hesitation !)
I red (here
http://biblio.uqar.qc.ca/archives/24791721.pdf, page 92) that efficiency drops with temperature increase but it is because they wanted a specific RPM and power output.
But we are ecomodding overly powerful engines so anything that drops down power hence fuel is interesting. By using less dense air, my ECU puts less fuel in the given capacity cylinders, I artificially downsize my engine.
Now that I think about it, this trick is not applicable to mechanical pump engines ... sorry HypermillerAX !