Temp gauge vs. mileage
I was on a long trip yesterday and was thinking over coolant temperature vs. mileage.
As some of you know, for no apparent reason, my mileage dropped from the traditional 20+ MPG recently to the 16-17 range. No CEL, no dirty plugs, no vacuum leaks.
However, I did notice that my temp gauge was indicating low compared to the reading I got with my laser heat gun. I swapped out the temp sender last weekend and the reading on the gauge returned to normal.
Previously on trips, my MPG was around 22 at a constant 80 MPH, and 20 MPG around town.
I had a 400 mile trip yesterday, same conditions, and pulled 25 MPG.
Since the Series II PCM apparently take it'* coolant temp reading from the gauge indicator as well, I have to wonder if a more accurate reading to the PCM resulted in the mileage increase.
Thoughts and opinions?
1999 SLE K engine