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Old 06-30-2012, 11:33 AM   #40 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
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Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 57.73 mpg (US)
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Dangerous and annoying: Pulse & Glide

Another comment:

The description of the Pulse & Glide technique in Increasing Engine Load – She's in it for the Pulse and Glide is only half right.

Also, calling the technique "dangerous [and] annoying" earlier, in Acceleration and Shifting: Horse Sense and Horsepower, is kind of a weak generalization that many here will disagree with. Obviously there are scenarios where that characterization may be true, but there are also scenarios where it's not true. (Just as there are times where, say, driving fast is both dangerous and annoying, there are times when it isn't.)

You more or less correctly describe the goal of the pulse as accelerating as close to best BSFC as possible. But the other half of the technique - the glide - isn't described well: You say, "Once you hit your target speed of 70 mph, you let off the throttle, and coast..." But that implies in-gear engine braking/deceleration fuel cut-off, which is absolutely the wrong way to glide.

The method for achieving excellent results when gliding is in neutral, with the engine off (maximizing coasting distance by avoiding compression braking & avoiding idling losses). Also, it doesn't include the caveat that this technique may not work well (for various reasons) with a torque converter-equipped automatic transmission.

I suspect some of the hybrid drivers may question your description of the parallel hybrid approach to P&G as well. (Hint: the best results come from avoiding use of the electric motor/generator.)
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