MPG - every little bit helps

[It's Just Eric]

I think that mpg is a rather crude mesurment for how much fuel is consumed. I mean, when idling, your pbviously going to get 0 mpg no matter how much fuel you actually use. As for fuel consumption while idling....I've left a car running overnight by accident once. The car was running for 14-16 hours, and consumed less than a quarter tank. So....if you spend 14-16 hours at a stoplight in say...a week...then I could easilly see the practicality of turning off.
All I know is if the 5 people in line infront of me turned their cars off, and had to restart before going at the green light, Somebody's horn would be blasting