I have heard a lot of questions about the safe and efficient operation of the Lycoming IO-360 in our DA40. I consulted the manufacturer and discovered that I have been passing along old wives tales. I apologize.
You can read the full article from the Lycoming Flyer here.
Yes, you can run the engine with manifold pressure (in inches) higher than RPM (in hundreds). After a review of the POH and this article, I now recommend it.