This article from John Deakin will sort out any arguments.
Its funny to listen to pilots perpetuating old wives tales after flying aircraft with rudimentry or no instrumentation at all. truth is, most dont know what they are talking about because there is no way of telling exactly what is actually going on inside the engine.
Better yet, anyone who realy wants to learn how to operate these engines should attent the advanced pilots seminar run by John deaken in the US where u get to operate a chieftain engine in the worlds most advanced test cell and you can see what is really happening.
http://www.avweb.com/news/columns/182107-1.html
http://www.advancedpilot.com/course.html