How To Adjust Your Indicated Average Fuel Economy

[RubyRed15GT]

As many of you know the indicated average fuel economy( mpg) found in the trip1 or Trip 2 display does not usually match the hand calculated. In my case the indicated has been .9 miles to the gallon more than the hand calculated. After some research and trial on my car, you can adjust this difference out by using the AFE Bias which is found in the Engineering Test Mode.

1. To get to the Engineering Test Mode. Search this site for instructions.

2. Be sure you have a sufficent sampling of fuel history logs to be able to be able to get a good idea of how far off the indicated is. I had over 18 months of fuel logs which included the hand calculated and the indicated mpg. You will need to get the average calculate mpg and the average indicated mpg.

• In the Engineering Test Mode scroll up or down using the left steering wheel controls (up or down). When you get to the AFE Bias screen you will see the number 1000.

• From what I have found this number represents the value of 1.000 and you can adjust it either higher by left arrow or lower by right arrow (left steering wheel control) by .001. Go right one click on the control the AFE Bias will show 999.

• To find out what number to input to the AFE Bias take your average calculated mpg and divide it by the average indicated mpg. In my case I had 17.64 calculated and 18.65 indicated which equals .945927 or rounded to .946. Using the right control button I changed my AFE Bias to 946. if your average calculated is higher than the average indicated you would get a number higher than 1. After 2 tanks of gas the indicate has been spot on for tank 1 and off by .1 for tank 2.

Hope you find this useful.

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[sigintel]

Nice! Way to represent for Plano!

 

[zuki_dan]

Thanks. I will try this with my car. My hand calculated is always 1.5 -2 mpg less than the computer calculated.

 

[jbailer]

Here's the video for the Engineering Test Mode:

[ame]

 

[zxd9]

Very cool. Got to give this a try.

 

[Stangnut]

Great post. Thanks!

What research led you to figure this out?

 

[RubyRed15GT]

Great post. Thanks!

What research led you to figure this out?

I ran a search on Google using the term "AFE bias ford". My hits lead me to a couple of sites in Germany that looked promising. Using Google translator I was able to get a concept on the bias calculation. My first attempt went the wrong way instead of being .9 it was 1.8 mpg off. After a few days of playing with some calculations and re-thinking the AFE Bias number of 1000 as 1.000 it started to make sense. Trial and error and a little wall banging :frusty:

 

[JohnDoe]

This is soooo useful, but I think I'll stick with my 15mpg on display instead of my real world 13mpg :/

 

[x_man586]

I will have to do this. It is kind of a pet peeve.

 

[Wblv17]

Thank you for the most useful post of the month.

 

[Evil Minion]

sub'ing to remember this for later!

 

[HoosierDaddy]

I love it!

Will adjust to match real world.

And I have to remember to set it to show double real life a tank before I sell the car down the road to impress prospective buyers. ;)

 

[GJarrett]

Also subbing. BTW I've owned several Fords and they all seem to be optimistic on their mileage computer displays.

 

[Evil Minion]

...And I have to remember to set it to show double real life a tank before I sell the car down the road to impress prospective buyers. ;)

:lol: Brilliant!

 

[Horse]

Nice!

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