Ya need compression release and the you keep the engine in gear to spin the compressor. Actually eCycle makes an adapter for connecting the AC compressor to an electric motor so you can run it with the engine off. Actually you want to run the AC under load so you don't loose so much gas and then when the engine is off or you are coasting then you switch off the AC.
I took a trip to Annapolis this past weekend to go visit some college friends, a little bit of driving around town, and then back home. All told it was 298.x miles on about 7 gallons of gas. That's puts me at around 42 mpg. I left off the tubing connecting the resonator chamber just to see if there was any noticable difference. So far I have found none for highway driving, which is probably the only good indicator of my actual fuel economy.
Since starting my new job I don't drive highway as much anymore. Typically I've been getting around 30-33mpg during the work week. However, overall I'm been driving less due to the shorter distance. Eventually I'll have to sit down and figure out how much this is saving me in the long run.
1) I already put 10k miles on it, and it's still going up (Note: I bought it in Feb.)
2) the front bumper has a scrape on the passenger side, but it's only visible if you get on your hand and knees.
Forgetting about the scrape, 10k on a brand new car in less that 6 months is not going to do a whole lot of good in terms of trade in value. A new EX with a manual would go for around 18k plus change. I still owe 11k on this car, with a trade in value of maybe 16k-17k.
It just doesn't reallly add up at this point. Maybe I'll trade for a used on once they start showing up.