(09-13-2009 10:12 AM)thomasbala Wrote:  You know what your mpg was before you modified your MAF. Now you're probably seeing great mpg gains, but they're false. go to the gas station
and fill it up slowly until the first automatic click-off. Note how many gallons it took. Go to "fillup" on the scangauge and enter the same number of gallons the pump said your tank took. Now you should be recalibrated. You should follow the 'fillup" ScanGauge procedure everytime you fill up. After a while Scangauge will get pretty accurate.

So, now we have mpg before you modified your MAF and true mpg after you modified your MAP. Note that the ScanGauge has no hook up to your gas gauge or tank; It's only hooked up to the diagnostic port and that just reads various sensors. [ScanGauge gets the mpg from their proprietary alogrithm that somehow calculates mpg from the sensor values.]