Originally Posted By: CharlieBauer
Originally Posted By: Kuato
It sure didn't in my old Jeep 4.0...Valvoline 5w30 conventional for 6000 miles, UOA said it stayed in grade.
Could it have thinned then thickened as it oxidized?
I also thought that a high Noack (14.4% per PQIA for Valvoline 5w30 conventional), means that the lighter fractions of the base oil will evaporate.
Certainly possible; however the recommendation was to extend to 7000 so I think it was good to go.
Originally Posted By: Kuato
It sure didn't in my old Jeep 4.0...Valvoline 5w30 conventional for 6000 miles, UOA said it stayed in grade.
Could it have thinned then thickened as it oxidized?
I also thought that a high Noack (14.4% per PQIA for Valvoline 5w30 conventional), means that the lighter fractions of the base oil will evaporate.
Certainly possible; however the recommendation was to extend to 7000 so I think it was good to go.