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Old 02-23-2012, 01:58 PM   #9 (permalink)
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RebCivic - '12 Honda Civic EX
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Originally Posted by euromodder View Post
Sure, but then you're braking (=wasting energy).

In the end, you'll use less fuel - even though the engine is idling and using fuel to do so.
I can't test this with my auto, but I assume you have. The steepness of the downgrade would certainly be a factor.
The difference is in the braking (DFCO / engine braking) - or not braking (coasting).
You'll coast far further than when letting go of the throttle and go into DFCO.
That's where the gain is.

(If not, the tranny has some kind of freewheel in it that automatically lets you coast.)

Coasting has become my main way of reducing speed
Huh? I was following you until this point. If by "coasting" you mean "shifting to neutral", isn't this a contradiction? How does shifting to neutral allow one to reduce speed? Oh! You mean via air resistance and road friction? OK, now I get you. But on a steep hill, you might need the DFCO/braking to avoid usafe speeds. I agree that the brake should be the last resort.
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