Quote:
Originally Posted by Christ
I don't like to go further than a few hundred feet, but I have no evidence that supports damage for short distance coasting, either.
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I know much has been made on whether or not the car is 'flat-towable' or not. If it's flat-towable, supposedly you can EOC to your heart's content. If it's not flat-towable, that generally means that the transmissions parts don't get lubricated when the engine is off, and so there is usually some distance/speed limitation on coasting listed in the owner's manual. Even so, the occasional coast to a redlight is probably no big deal. After experimenting a little with it, I didn't see any significant fuel economy increase for my vehicles -- mostly, I think, because there were really only a couple of places in my usual commute where I felt comfortable doing it. (Besides, I like having power to the brakes and steering.)
Regarding the break-even point for fuel consumption, according to the BMW owner's manual, that point is reached after
four seconds of idling. Now, that doesn't take into account additional wear and tear on the car for each additional startup, so take that with a grain of salt. My own rule of thumb is basically I'll let it idle for 20-30 seconds, but I will shut down if I
know the wait will be longer AND if the engine is already at operating temperature AND if I haven't shut down within the last 5 minutes or so. (AND if Mrs. JKP1187 isn't in the car, too, because she'll no doubt want me to keep the HVAC running.
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