Folks Of Interest From Question hanging from the Spark Plug thread:

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Now I admit having some trouble with McKim's meaning on this one and I asked at the time " What that "placebo effect" might be?
Well there Mr. MCjim ??

 

You always remember the failures of the brands you think are duff even though they might be no more frequent than the brands you think are ok.

 

Duff meaning, ????? Sorry no meaning in US english that I know of.

 

****ola...
it's all in your mind.

 

Duff = NDG

 

I’m still running strong on my Almquists from back in 1952! Lol I couldn’t resist