Maximum safe mileage for Syn switch

[Drewhenry]

I recently made it past the 100K mile mark. Is it too late for me to switch to synthetics without an increase in oil consumption or other mal effects? I am considering going to Valve premium blue extreme 5w40, or Amsoil 5w30HDD



Andy

 

[steved]

I changed to Schaeffers 5w40 Series 9000 full syn at 162k without issue...

I would only think you should have trouble if you ran garbage oil in the beginning or neglected oil changes...

 

[Johnstra]

You'll probably be ok switching. I was running Schaeffer 9000 in mine (it's a very good oil), and after a couple of changes and having the oil analyzed, I've found that about 10k is the farthest I can go. After that the TBN drops and I have to dump and change. So running the expensive synthetic isn't paying off for me. I've decided to go back to Delo and change ever 7500 miles. I run Gulf Coast O-1 bypass just like steved, so I feel fine taking the Delo out to 7500 miles.



Your truck may be able to go much longer on synthetic than mine. Each engine is different and analysis is your ticket for finding the sweet spot and for catching problems early.



-john