I am not trying to debate the definition of oversquare which is cut and dry and very clear and was only pointing out the associated rules of thumb have gray areas which can be very useful for economy. I believe the link is a well written article by the editor in chief of a pilots association and I respect the guy. His statements about reduced engine speed reducing friction are spot on and germane to the topic. I possibly could have gone on the low side of a safe idle and I plan to play with it a bit and see how much it affects my city mileage, because that is the reason I want for a lower idle. I don’t mind being the guinea pig or canary so to speak if others can benefit from my data, just don’t shoot the messenger. This also could lead to other solutions to the low oil pressure such as an electric oil pump that is set to kick in at low RPMs. Obviously the best savings at a light is to turn the engine off but then you have to be concerned about starter wear and tear. It seems that there are many examples on this site of thinking outside the box to gain efficiency.
Cheers,
