Noticed today on way back from a freinds house my mpg avg was acking weird it was going from 19.6 then rapidly higher to 21.3-24.5 and so on... then when i was idle at a light it went down rapidly???? never has happened before always a steady 19.6 give or take a couple of tenths... why would this just happen, any clue. Thanks

 

I have noticed this when I first reset it. The more miles you put on the steadier it gets.

The one thing I have noticed is that if I'm driving around and I average lets say, 21.7 MPG and that's what it shows when I put it in the garage. The next day I get in it it and start up and it reads 18.4. I would expect it to climb back toward the 21.7 very quickly, but it doesn't.

Kinda weird.

 

It works off the vacum (sp?). If you are driving fast and take your foot the gas, average MPG goes really high, then it adjust. It's goofy. and, it's probably just an 'estimate' anyway.

 

if all else fails hit the reset!!