Originally Posted by kingme
Gordy, do you plan on analyzing your oil? I'm curious if the new tune is rich for safety, causing your lower mileage. A UOA might show high fuel dilution which would lower flashpoint and viscosity. Maybe the tech recommended 5W-40 because he knew a 5W-30 would be further weakened by fuel dilution.
Of course, this assumes the tech knew anything about your special tune
. Regardless, still curious.
Oh yeah! I have my blackstone sample bottle sitting on the shelf. This Map has to be silly rich compared to the first. I had the cruise set this morning @ 73 MPH, 6th gear, Intelligent mode, I watched the meter drop 0.5 MPG in the A/C OFF , 62° 35mile ride to work. For a total WHOPPING 20.1 MPG ... Nice !