# Economy MPG Readout Oddities.



## Premier17 (May 20, 2017)

I leave my center information screen always on the average MPG readout and I've noticed odd behavior since new. Say, my average MPG over the last 50 miles is 31 MPG. If I"m driving on the highway with cruise set, and the instant MPG readout is reading between 38-45 MPG for example, I can watch the average on the dash actually DROP while the instant constantly remains higher than the current average. I've also had it where I've been stopped at a stop light before not moving, and the average MPG will slowly crawl up while sitting there. (even while auto-stop is on, or the instant is reading 0 MPG.) I don't know if it just has a big delay in its calculations or what, but it is really odd. I haven't seen a vehicle do this before with the average MPG. Has anyone else noticed this? I have the upgraded cluster from the sun and sound package BTW. The average is pretty spot-on accurate, but logically to see the numbers change in a way that mathematically is impossible has me a bit stumped.


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## georgecdisc (Mar 7, 2018)

In regards to last X miles, think of it as a rolling average. If 49 miles ago you were getting 99mpg coasting down a 1 mile hill but 0 miles ago (instant economy) you are getting 40mpg... Then you effectively are getting worse economy which makes your X miles avg mpg go down.

I can't explain the at a stop scenario


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## firehawk618 (Feb 24, 2013)

After watching the behavior of mine since new I can confidently say that they have built in a buffer. So in other words when you see it going up at a stop all it's doing is slowly correcting the reading you have accomplished before stopping vs just quickly ramping it up to the correct current number.

I have never seen it quickly increase nor decrease. Always a slow climb / decent as it settles into whatever the average is.


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