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Old 08-29-2013, 02:38 AM   #2 (permalink)
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Lean and Mean - '98 Honda Civic HX
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The DFCO info should be in your factory service manual. Your instrumentation will let you know, as it will display 9999 MPG on the instant MPG gauge.

DFCO is very different than EOC. With DFCO, you are using no fuel, but you aren't coasting efficiently. The mass of the drivetrain, as well as the force required to compress intake air, is creating a brake that slows the car down quickly.

I can't think of a situation where DFCO is better than EOC. For example, if you see a red light ahead you should immediately cut the engine, coast to a stop, and not idle. With DFCO you would not be able to coast as far to the stop, and you would still be idling once you got there.

For P&G DFCO would drastically reduce the distance you could coast compared to EOC or neutral coasting.

If you know that you need to decelerate ahead, say going from 60 mph to a 45 mph zone, DFCO could be used instead of your brakes. The better method would be to EOC sooner so that you have a long coast and you get down to the desired speed.

DFCO is useful when you don't want to use brakes, like going down large hills. But that is pretty much the thing, DFCO is a brake.
1998 Honda Civic HX - My Project Thread

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