flush oil?

[MattM]

Maybe an old question, I decided to try synthestic (Rotella) oil. Do I need to flush/drain out my old oil in the system or can I just drain the old oil from the oil pan and fill with the new synthetic?

Wondering whether any issue if there is some old dino oil getting mixed with the new synthetic oil?

 

[no-red 6 0]

drain and input new...

i have switched from factory to rotella to ams to factory to ams.....blah blah blah - all w/ a blackstone report and have had NO ISSUES.

 

[dpantazis]

rotella's official stance is that there is no problem switching between the two.

there is/was a FAQ question on this at the rotella website.

iirc, the rotella blue bottle synthetic is a semi-synthetic. the only thing left in the engine at oil change is what is in the hpop, so its like 1 qt old to 14 qts new, its gets diluted pretty good.

 

[MattM]

I changed over to the Rotella synthetic 5w-40 from the Rotella dino oil. Truck does seem a bit quieter and smoother (engine wise) now. Start ups were starting to get just a little bit slower with temps in the 20's-low 30's.

Will be interesting to see if the synthetic oil helps that at all?