Oil Life Computer (reset to 100%?)
 

I changed the oil in my wife's 07 Exp (XLT 4x4) w/ Mobil1 5w20. I started it up & went into the computer to reset the oil life indicator. When I reset it, it only went to 90%. I expected 100%... I tried it a few more times & could only get it to go to 90%. Any ideas why? The book says it should go to 100%.

Thoughts?

-robert

Maybe there was still some Burned out oil left on the engine walls which got mixed with new oil and sensor senses it?

Navigate to the oil life display and reset it like you would after an oil change, once reset pushing the button again should de-increment the oil life by 10%, repeatedly pressing this will eventually get you cycled back around to 100%. This will set your default starting oil life, as I understand it 100% = 5000 mile oil changes, yours seems to be set on 4500 mile oil changes, 60% would be 3000 mile changes. There is no oil sensor, at least not one that measures the condition of the oil, instead the oil life is based on a calculation that takes mileage and time into account, it may also incorporate more factors but I can’t be sure. Again, this is as I understand it.