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2004 Buick Rainier Question: 14.2 mpg highway & no error codes or lights

 

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41willyguy, 4.2L 6 Cylinder, San Diego, CA, July 11, 2010, 10:52
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fuel mieage on local & highway, using high or low grade fuel, increasingly getting worse. Bought from dealer 1 year ago doing 16.0mpg, now down to 14.2mpg. no signs anywhere. mechanics won't look at it without a code to trace.

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  • Answer #1

    patrick mannion from Greg Solow's Engine Room, July 11, 2010, 11:00
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    Check this government website for 2WD Rainier. http://www.fueleconomy.gov/feg/findacar.htm

    They are not brilliant for MPG but some tires even can help fuel economy, (less rolling resistance). I wonder on a scan tool what the fuel trim figures are Long Term Fuel Trim figures show if your car's computer is adding or taking away fuel which may not yet have set a code.

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  • Answer #2

    Visitor, July 31, 2010, 13:16

    you may want to seek professional help because my 2006 AWD Rainer needed the stabiltrac serviced and after that the fuel mileage went from 15.7 to 19 mpg highway

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