I finally switched from conventional oil to synthetic in my old 7.3 and wish I did it sooner

Ran Rotella 15w40 in my 2000 F250 for the first 180k miles because that's what everyone told me to do. Last oil change I put in full synthetic 5w40 on a whim. Cold starts this winter in Maine went from 5 seconds of chugging to firing up instantly. Anyone else make the switch late and see a big difference?

3 comments

3 Comments

diana6171mo ago

That chugging on cold mornings used to drive me nuts, I know exactly what you mean. I switched my 94 F350 at 160k miles and the biggest thing I noticed was how much cleaner the oil stayed between changes. The synthetic didn't turn into sludge as fast, even with my long highway runs. Did you check if your high pressure oil pump started sounding quieter too?

kelly6381mo ago

Yeah that bit about the oil staying cleaner really hit home with me. When I did my swap on my 2000 F250 at around 120k miles, I noticed the same thing. The synthetic just didn't break down as fast, especially with all the idling I do in the winter plowing. I also swear the high pressure oil pump got a little quieter after a few thousand miles, but that might just be my ears playing tricks on me. One thing I will say though is make sure you're using a good synthetic that's rated for diesel, not just any off the shelf stuff. I tried a cheap brand once and it didn't hold up near as well as the name brand stuff in my experience.

michaeltorres1mo ago

Used to swear by conventional till I tried synthetic in my 7.3, definitely changes your mind on cold mornings.