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Old 11-04-2012, 07:27 PM   #26
Bluefoton
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Fuel is needed to maintain RPM above or at idle. If you're in neutral, nothing drives your engine but the combustion.. so you use the 0.25gallons/hr for that. If you have a MT, and are coasting, the wheels drive the engine. The ECU realizes it needs no fuel to make the engine turn, so it cuts the fuel intake to zero. On long downhill in-gear coasts you can actually see the coolant and oil temp drop below nominal values, as the engine spins cold..
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Old 11-04-2012, 08:58 PM   #27
goregasm
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Quote:
Originally Posted by Bluefoton View Post
Fuel is needed to maintain RPM above or at idle. If you're in neutral, nothing drives your engine but the combustion.. so you use the 0.25gallons/hr for that. If you have a MT, and are coasting, the wheels drive the engine. The ECU realizes it needs no fuel to make the engine turn, so it cuts the fuel intake to zero. On long downhill in-gear coasts you can actually see the coolant and oil temp drop below nominal values, as the engine spins cold..
Proof?
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Old 11-04-2012, 09:04 PM   #28
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Quote:
Originally Posted by goregasm

Proof?
You can feel when the fuel is reintroduced, there is a tiny jolt. Most manuals this happens at 2000 rpm, not 100% sure on this one
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Old 11-04-2012, 10:58 PM   #29
Commander Keen
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Quote:
You can feel when the fuel is reintroduced, there is a tiny jolt. Most manuals this happens at 2000 rpm, not 100% sure on this one
Using a scan tool, I've seen as low as 1100 on mine.
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Old 11-05-2012, 05:50 AM   #30
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Quote:
Originally Posted by Commander Keen

Using a scan tool, I've seen as low as 1100 on mine.
I should really hook mine up
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Old 11-05-2012, 01:32 PM   #31
AcquaCow
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I have many logs that show my injectors shut off when I coast in-gear... definitely no fuel used until you get back down to about idle RPMs..
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Old 11-05-2012, 01:42 PM   #32
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Quote:
Originally Posted by Bluefoton View Post
Fuel is needed to maintain RPM above or at idle. If you're in neutral, nothing drives your engine but the combustion.. so you use the 0.25gallons/hr for that. If you have a MT, and are coasting, the wheels drive the engine. The ECU realizes it needs no fuel to make the engine turn, so it cuts the fuel intake to zero. On long downhill in-gear coasts you can actually see the coolant and oil temp drop below nominal values, as the engine spins cold..

Question I have always had is in regard to coasting in gear vs. coasting in neutral in regards to distance one is able to go before needing to hit the gas pedal. From my experience being in gear adds more "drag" and I feel like the car won't roll as far or as quickly. When in neutral it will roll faster and farther even if it uses 0.25 gallons/hr. Wonder what the difference comes out to be if there is any difference when you account for that?
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Old 11-05-2012, 02:24 PM   #33
Commander Keen
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DFCO (deceleration fuel cut-off) produces infinite instantaneous MPG and will raise your average as long as you're moving.

If you see a red light up ahead, DFCO makes perfect sense. You'll want to pick a high enough gear that you're not slowed too quickly, but a low enough gear to maximize the amount of time the RPMs spend above 1100 or so.

I think using 40-70% throttle up hills in 5th and 0% on the way down gives better MPG numbers and more stable speeds than the feather-the-throttle method.

Last edited by Commander Keen; 11-05-2012 at 04:06 PM.
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Old 10-18-2013, 07:07 PM   #34
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So sitting here in the 60f weather. ECU reports between 7.4 and 8.0cc of fuel per minute. Let's say 7.8 and be liberal.

That's 0.12 gallons per hour. **** me that's low.

Edit: now that it's completely warmed up its at 0.107gph. ****. Me.

Last edited by goregasm; 10-18-2013 at 07:18 PM.
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Old 10-18-2013, 07:32 PM   #35
lymphomaniac
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I wonder how idling the engine until the blue light goes off before driving compares to the fuel consumption of driving the vehicle with the blue light on until it goes off?
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Old 10-18-2013, 10:49 PM   #36
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Quote:
Originally Posted by lymphomaniac View Post
I wonder how idling the engine until the blue light goes off before driving compares to the fuel consumption of driving the vehicle with the blue light on until it goes off?
Probably the same.
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