C. I do apologise if my original reply was a bit abrupt but I honestly thought you were giving us a wind up.
You say in your reply to dragchute, what is the point in using mixture if several seconds later you close the throttle.
The point is what happens in those few seconds. You start with an engine turning at say 2600 rpm developing full power. You close the mixture which "puts out the fire". The cylinder is still full of air and while being compressed
a) prevents a sudden reversal of load on the piston/conrod/crankshaft assembly and
b)starts the engine slowing down (no power stroke and work done compressing the air)
Now when the throttle is closed the engine is no longer doing 2600 rpm (I have never looked closely but I would imagine around 1600 rpm or less). The reversal in loads will now only be a very small fraction of what they were.
You again talk about what the manufacturer states about operation of his engine. If you read Lycoming Service Bulletin 245 you will see that Lycoming are unequivocal in stating that the way to fail one of their engines is to use mixture "... if the power was abruptly terminated, it must be accomplished with the mixture control."
Because the NTSB later came out and said that "... such procedures at traffic pattern altitudes may not permit instructors enough time to overcome possible errors on the part of the applicant" Lycoming (most likely in regard to possible legal issues) softened their position and said "... simulated engine-out operation at the lower altitudes should be accomplished by retarding the throttle, and this should be done slowly and carefully to avoid engine damage or failure. " This does not sound like the statement of someone who feels that failure with the throttle is the best method for his engine.
As I just renewed my instructor rating yesterday after a break of several years, I am really enjoying this discussion and look forward to continuing it in an amicable fashion.