'99 Explorer, V6, 111K miles.
PO used standard petroleum base oil.
Too late to switch? If not, syn blend or full syn better?
Will be doing some serious highway miles few times year, otherwise city driving

Tnx
Skysarge

 

You just asked a question that I have heard many times and debated for hours LOL. Many say that once an engine gets over break in miles with a non-synthetic, synthetic is no longer an option. I have heard this from not only certified mechanics but from the manufacturer’s reps as well. Maybe a personal thing as I have yet to find a “study” that has been done on it.

I believe this is more of a personal opinion than a fact based one and I would LOVE to see what everyone has to say about it. My personal opinion and I am an odd sort. I would go synthetic. First change to 3k miles and after that every 7k. Two and a third times the miles on the change make the money worthwhile.

Now to benefit… true story… I asked a rep from Castrol (my preferred brand) a similar question one day. After going back and forth for a few minutes he asked me how long I had been smoking. When I answered over 30 years (much more than break in LOL) he asked if I quit the next day, would I see a benefit. Needless to say I have been using synthetic from that day on.

But another thing to keep in mind is the quality of both the oil and the filter.
I look forward to seeing the responses to this.
Good question.

 

Sometimes this is like a loaded question.
From my own experience and what I have observed.
It seemed to me, when the engine was new and I installed full synthetic motor oil the rings for whatever reason took much longer to seat (conform to cyl shape) . New engines are today made to much closer tolerances and will most likely be fine with synthetic from the start. But , it seemed it required mineral base oil for the first few thousand miles and the rings seated faster. After that full synthetic seemed to be the oil of choice for many reasons like easier cold starting, longer lasting coating on friction surfaces, more resistant to deterioration among other things . I can't truthfully say if it is better to go to full synthetic on a high mileage engine because the wear it is supposed to prevent has already taken place.I have installed full synthetic in every engine I have including generators, mowers, tractors and of course the cars and trucks. I have been very satisfied with the performance and results and depending on the mileage of the vehicle and consider it even with high mileage. This has only been my observation.