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Old 03-14-2014, 08:24 PM   #41 (permalink)
Ecky
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Join Date: Dec 2011
Location: New Zealand
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ND Miata - '15 Mazda MX-5 Special Package
90 day: 39.72 mpg (US)

Oxygen Blue - '00 Honda Insight
90 day: 58.53 mpg (US)
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Quote:
Originally Posted by Mista Bone View Post
You should be using the GSR 5th but with ECU tuning you can get by with the higher rpms. LS motor with bigger bore is happier at a lower cruising RPM, but that is getting into some engine dynamics that isn't understood here.

Imagine doing 70 mph in 4th gear and getting 47+ mpg.

Vacuum gauge and driver mod is the first and best gains, then ECU tuning.

Myself I tend to use very light throttle, enough to pulled to 3500 rpm, then shift to next gear while not lifting off the gas pedal.

I hope to set up a video camera in the car to show how I drive the CRX and my old HB, then maybe others will understand.
Appreciated. I'd love to swap out my 5th for an LS 5th but I don't think I have the proper equipment to drop the tranny in my apartment complex parking lot.

Just went out and sat in the parking lot and rev'd the engine in neutral (fully warmed up), and measured the fuel used. These are the figures I came up with, which I bet are accurate within about 10%:

Idle/750RPM: 0.22 Gallons/hour
1000RPM: 0.28 G/h
2000RPM: 0.50 G/h
3000RPM: 0.91 G/h
4000RPM: 1.10 G/h
5000RPM: 1.50 G/h
6000RPM: 3.04 G/h



Possible parasitic loads are power steering, a fully battery with minimal electrical load, oil and water pumps, internal friction, pumping losses.

For reference, cruising at 75mph (4000RPM) I get around 30MPG (or I did before my recent aeromods) which calculates to approximately 2.5 gallons per hour. 65MPH (3500RPM) / 37mph is around 1.9G/h. 38mph (2000RPM) / 47MPG is around 1.24G/h.

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