Shutting off the engine at traffic lights (was-Want to Hypermile Please Help )

[Harpo]

My magic number is 30 seconds EO if I know the light. I know my home-work-home route so well, I can time most lights and rarely have to stop. There are three that are impossible to time becuase they are at exits. All three are 2-3 minutes long. I can tell you that idling at "one" kills my trip average by about 1mpg on 26 mile commute. If I idle all three, I'm down 3mpg. Even then, I can see the light change on two of them 1000' down the exit, then kill the engine for EOC right then. I can get an extra 20-30 seconds of EO time just by being watchfull!

However, July and sweltering humidity is upon us. I doubt I'll be setting any recos for July and August. The AC will have to see some use, or I'll be a sweat rag by the time I get to work. The trip home is impossible without AC.