ScanGuage reports high MPG

[jorlee]

Ya, high as in ending trip total of 29.9 MPG

This is in a Street tune from Innovative, that i received yesterday.

Drove 73 miles one way today with it telling me that trip achieved 31.1 MPG.

Not believing what it told me, I drove on the way back at 60 mph for 5 miles to check the accuracy of the speedo, yep checks out fine.

The drive back home yielded 28.7 mpg.

That's a combines trip total of 29.9 MPG.

I'm not so sure I believe it myself, but I had filled it up to the neck, had 55 miles on it before I tuned it, now has 201.1 miles with 1.5 needles above 3/4 of a tank left, or so it says.

I may have to drive just to use up the rest of the tank, which is shows 21.1 MPG for the entire tank, so far.

Is my Scan guage lying to me, or is this going to have to wait for the end of the tank? I'm very confused, and very very baffled.

P.S. Previous high MPG was 16.x MPG I calculate out each fillup, just to check. The Scan guage is always with in 1 MPG, usually on the low side.

[vitalidle]

Yep. My dad originaly owned my superchips when he had an 02 7.3 and his overhead guage read as high as 28 mpg so tuners will funk up the overhead gas gauge. I have an xlt so i can't tell you what it says on mine Best thing is to always use the overhead as a general idea, but hand calc for accuracy.