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Old 12-27-2007, 02:56 AM   #5 (permalink)
AKA Queso Grande
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Join Date: Dec 2007
Location: San Diego
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Queso Pequeño - '90 Geo Metro Convertible LSi

The Blue Pill - '93 Honda Civic Hatchback DX
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Originally Posted by MetroMPG View Post
That said - a question about your technique (to clarify what we're talking about)...

If you're talking about turning the engine OFF where you were previously left it ON while not under load (such as idling while coasting with the clutch in, or the tranny in neutral down an off ramp, for example), that's probably not quite the same thing as pulse & glide.

I'd call that engine-off coasting (EOC).

EOC will save you fuel for sure, but not to the same extent as P&G.
I'm new to this, so I'm not quite sure what I'm doing. Here in the coastal regions of California, it's all valleys. So you can find yourself pulsing up a hill and gliding down it, where they lineup pretty well for pulsing and gliding. To be pulse and gliding here with only regard for your target speed will find you downshifting and wasting gas to make it up a hill. There's few stretches on my commute that remain level for any sizable distance. As far as gliding down an off ramp, it's a crap shoot here - city planners in San Diego decided to go for variety. There's many places where ramps alternate as overpasses and underpasses like clockwork, some of those are a straight shot and some have you do a 180, and many have a signal just to get on at heavy traffic times (halting you where you would have gained from the overpass on ramp slope). That was a bit of information, my point was that an offramp underpass is the least significant place to coast on my commute.

Anyway, my current trial into this P&G/EOC world has me targeting 70mph. I'm hitting about 80 and letting it go down to about 60. I know going slower would be more beneficial, but I'll check out that trade off as I go.* I'm not religiously maintaining the target speed due to all the constant changes in elevation and traffic speeds, so I guess I'm just opportunistically EOC and trying to P&G where I find it safe and logical to do so.

*Another argument for the higher speed is that it's hard to retain any constant motion in the slower lanes at peak traffic times, where you can easily pulse to the fast lane and just merge to the right once or twice as you glide (we're five lanes wide nearly the whole stretch). If you were doing this in the slower lanes, you'd come to nearly a stop (if not a complete stop) very often. Luckily I go the opposite direction of heavy traffic, so coming to a stop on the fast lane only happens when there's an accident.

Last edited by dissimilation; 12-27-2007 at 10:33 AM..
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