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Old 05-23-2008, 10:00 AM   #8 (permalink)
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Originally Posted by ncc74656m View Post
My issue with the appropriate driving style for maximum MPG is one of several. First off, NY roads, both highway and street, are just about never suited to most of them, everything from steady speed to P&G techniques. It's just a fact of life most of us live with in this area. In other areas of the nation it's easier to do, I believe. Remember, it's not just us on the road, it's everyone else that helps dictate our driving style.

As noted in my original post, when I do take into account consistent driving, there is no doubt that the consistency helps greatly. Also, staying at the recommended 55 MPH is another tremendous boost. This is the type of situtation where I'd like to employ things like the aero mods. I'm doing this activity largely out of an interest in the subject and proof of concept rather than significant changes to my driving style.

Oh, a small aside for an update to the P&G techniques write-up. Most modern manuals are equipped with a fuel saving mode that causes the engine to kill the injectors while the car is coasting in gear. It does induce drag, naturally, which means that some sort of research here on the comparative costs/benefits of the loss of coasting difference over neutral, but it's worth mentioning anyway.

Ideal situations are really never there for driving efficiently. I used to think the same thing as you that "I can't do that where I live, theres too much traffic". Then I tried it for one tank and instantly saw a 10 mpg jump into the high 40s in the Paseo. From then on out I kept on doing it. These techniques really can be performed anywhere at any time. The more you use them the more natural it is and it just becomes the way you drive instead of a chore.

You are right about fuel cutoff happening in gear. However, the pumping losses from the engine drastically reduce the gliding distance to the point its not even worth it. Coasting with the engine on is still more efficient than coasting in gear. Coasting with the engine off (bump start when you need to pulse) is the most efficient. If you do try to do this try it out in a parking lot first as it does take some practice. However, I do use fuel cutoff in gear when I am coasting to a stop sign, or know I need to slow down faster than just coasting in neutral.
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