Whenever I see idling mentioned I think of the farmer who left his truck running for over an hour and a half outside an implement dealer I was auditing. All I could think was how far I could have driven on that fuel wasted. Or that what he used driving into town would have likely gotten me 120 miles home! I'm resigned to thinking that's where all I save ends up going. All our conservation might harvest a hill of beans, so to speak.
In the larger scheme of things I mention my mileage to my jet jockying nephew and he says he measures fuel consumption in gallons per mile!