[sheepdog 44]

As a purely academic exercise, i decided to see if i could determine the engine efficiency of Lean Burn in a Honda Insight engine from MetroMPG's real world testing. Well, the Former UFO is not stock, so the one constant i had to approximate was the CD. Stock cd is .25, UFO is under .25cd. So take this approximation with a grain of salt. Also the MPG calculator neglects certain km/h values, since the primary values are in mpg. For example, you can not find mpg at 70km/h!

MetroMPG's real world numbers were compared to a theoretical Honda Insight using the Aero/RR/MPG calculator, which was really informative, since any unknown variables are accurately expressed in the real world mpg he got.
[QUOTE=MetroMPG;326520]

Raw numbers: (All values are for Lean burn in 5th gear)
Speed ........... AVG ..........

km/h . mph . MPG (US) ENG EFF% .....%MPG Gain vs non LB

50 ... 31.1 ..... 130.9 ...... 18.7% ................00%
60 ... 37.3 ..... 121.5....... 22.4% ................12%
70 ... 43.5 ..... 113.9 ...... 24.7% ................24%
80 ... 49.7 ..... 98.0 ........ 25.2% ................27%
90 ... 55.9 ..... 88.5 ........ 26.5% ................34%
100 .. 62.1 .... 81.3 ........ 28.1% ................42%
110 .. 68.4 .... 67.1 ........ 25.9% ................39%


You can see engine efficiency goes up with speed, as the engine experiences higher loads and rpm drops. Those are pretty good numbers for an engine experiencing low load on a steady flat road. Lean Burn nearly approaches the engine efficiency of high load in a pulse and glide regimen. Which would be the condition where an engine experiences peak efficiency. And corroborates the story that Lean Burn gives more or less the same mpg as Pulse and Glide at certain speeds.