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Old 03-27-2014, 02:48 PM   #26 (permalink)
jedi_sol
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Join Date: Mar 2009
Location: Tustin, CA
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2013 STi *SOLD* - '13 Subaru Impreza WRX STi
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90 day: 26.59 mpg (US)

1996 Geo Metro *RETIRED from Ecomodding* - '96 Geo Metro Base
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Quote:
Originally Posted by johnlvs2run View Post
That's an interesting idea. However, my car uses .14 gallons an hour while coasting in neutral. Wouldn't constant blipping of the throttle use more than that?
When i "blip" my throttle, its more of a gentle continuous tap. it's not the kind of "blip" i would use when rev matching the engine/transmission (similar to your learning of bump starting )

On my car, the scangauge shows that when i step off the gas and shift to neutral, the fuel injectors cut off for a split second. Then every time i tap my throttle, the scanguauge shows 9999mpg. So the ecu is detecting "step off throttle...cut fuel...step off throttle...cut fuel...step off throttle...cut fuel."



So there is definitely a correlation between speed/throttle position/fuel injectors.

Here is my ABA TESTING:

I changed up my testing method to eliminate more variables. This time, I drove up to 50mph, shifted to neutral to coast, then when I hit 40mph, I hit RESET on Torque, then when I hit 20mph, I hit RESET AGAIN. This way, I only measure the amount of fuel used while coasting. I eliminate the variable of my foot accelerating too hard.

I also measured using 6 decimal spaces, to allow more accurate detail in fuel used.

A1 Runs – Straight neutral coasting from 40mph down to 20mph
0.003973
0.003607
0.003754
0.003500
0.003657
0.003907
A AVERAGE – 0.003733 gallons/fuel used

B Runs – Blipping throttle while coasting from 40mph down to 20mph to simulate EOC event
0.0015200
0.0007780
0.0001470
0.0009400
0.0007230
0.0006480
B AVERAGE – 0.0007926 gallons/fuel used

A2 RUNS
0.003673
0.003458
0.003368
0.003382
A2 AVERAGE – 0.00347 gallons/fuel used

A averages – 0.00362 gallons used
B averages – 0.0007926 gallons used

78.11% improvement over traditional P&G

However, this phenomenon may only be present in cars with "throttle by wire." I'm not sure if this phenomenon occurs with older cars with "throttle by cable/butterfly."

Since you have an Ultra gauge, and if you are curious, i urge you to see if this technique might work on your Civic.
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Last edited by jedi_sol; 03-27-2014 at 02:58 PM..
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