Thread: 40 mpg s10 2.2L
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Old 02-06-2012, 01:19 PM   #21 (permalink)
JRMichler
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Join Date: Feb 2011
Location: Phillips, WI
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Nameless - '06 GMC Canyon
90 day: 35.72 mpg (US)
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At part throttle, the fuel system runs about 14.6:1 fuel air ratio. At wide open throttle, that increases to about 12:1. The increased fuel is good for power and knock, bad for gas mileage.

If your rear axle ratio is too high, forcing you to drive at WOT, you can get worse mileage. That's why the comments about needing LRR tires and aero mods to run a taller rear axle ratio.

On the Ultragauge, look for a display of OPEN/CLOSED LOOP. Closed loop is the leaner economy fuel air ratio, open loop (with a warm engine) is the power ratio.

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The vacuum gauge plus wheel covers helped increase summer 2015 mileage to 38.5 MPG, while summer 2016 mileage was 38.6 MPG without the wheel covers. Drove 33,021 miles 2016-2018 at 35.00 MPG.
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