Posted for "Dan & Kari Olsen" <olsen25@comcast.net>:

 LML Gang,
 
 
 
 To chime in on the recent thread about LNC2 efficiency, I pulled up some
 GAMI lean tests I have done over the years and have attached them.  The
 interesting note here is that both tests were conducted at pressure
 altitudes of 13,300' and virtually identical atmospheric conditions,
 although the tests were taking 6 years apart.  Also, the older test is when
 my plane had dual Slick mags and the newer test is when I replaced the right
 mag with a Lightspeed Engineering Plasma III electronic ignition (left mag
 remains unchanged).
 
 
 
 Here is a brief summary of the data:
 
 .         Power plant setup is: stock Lycoming IO-320-D1B, 160HP, Hartzell
 70" 2-blade CS prop (factory recommended model)
 
 .         With dual mags my engine got rough just as I approached peak EGTs;
 with one EI it gets mildly rough about 30-60deg LOP
 
 .         I didn't record the spark advance, but I seem to recall that at
 these conditions it is advancing somewhere around 35deg.
 
 .         The CHTs in these charts are all probably a little high because I
 did not wait long enough between leaning steps for the temps to stabilize.
 In practice at 13,000' I am now seeing CHTs running 320-330F.
 
 .         For a target cruise speed of 184KTAS, the fuel flow has dropped
 from about 6.6gph to 6.1gph (8% lower).
 
 .         At target speed of 184KTAS, efficiency has gone from 27.9nm/gal
 (32.1mpg) to 30.2nm/gal (34.7mpg).  Increase of 8%.
 
 .         More aggressive leaning, at the sacrifice of some speed will get
 you even better efficiency.
 
 
 
 35mpg at over 210mph - not too bad!  This is as efficient at my Toyota
 Corolla at about 3.5x highway speed.  And I get to go point-to-point.  BTW,
 I beg to differ with Steve Jobs calling the iPad a "magical device".  These
 airplanes are truly "magical devices"!!
 
 
 
 Have a look at the attached charts.  I welcome feedback and questions.
 
 
 
 Cheers!
 
 
 
 Dan