Mpg gauge effected by tune?

[Jeremy05]

I just got my Blackbear tune installed yesterday and I noticed my my dash instant mpg gauge is now all over the place. Has anyone else experienced this problem after a custom tune? Before the time my instant mpg gauge was fairly steady. Now it jumps up to 70-90 MPg every time I let off the gas.

 

[swathdiver]

My instant has always moved all over the place even before my BB tune. It's the long term one that's more stable the further along it gets from the reset. Welcome aboard btw, Jeremy.

 

[niely]

The instant will change every second you drive. If you do the trip MPG it won't be 100% accurate. In order to get the most accurate reading after a tune, just do the math manually from the main spedo/trip. Really also changes if you did a different size tire swap etc.

 

[randeez]

It's not that it has "changed" anything....the tune probably reset all the historical data given for mpg. so instead of trending mpg over however many miles it's been since reset before> ie 50,000 miles and X amount of fuel it has a good idea of how far the next tank will get you. the computer just doesnt have a 50k mile time line of history to pull from, so it appears in real time that you're either going to go 50 miles to a full tank under hard acceleration (instant showing 2mpg) or 1200 miles while coasting (instant showing 70+mpg)

 

[swathdiver]

My DIC's calculations are nearly spot on.

 

[BlackBearPerf]

I just got my Blackbear tune installed yesterday and I noticed my my dash instant mpg gauge is now all over the place. Has anyone else experienced this problem after a custom tune? Before the time my instant mpg gauge was fairly steady. Now it jumps up to 70-90 MPg every time I let off the gas.

Hello Jeremy, we have not manipulated the DIC reading in any way. The decel fuel cut off function is kicking in more rapidly now, which is resulting in more time shown on the DIC where no fuel is being used at all.