quote:
My point is not that extended OCI's are 'bad' my point is that a recomendation of extended OCI's across the board is a dangerous idea.
Here's where we get into the subjective gray area. Some refer to factory recommendations as "extended drains" ..when they're only extended from that person's assumed baseline.
For me, extended drains are those that exceed the manufacturers recommendations when qualified by their conditional limitations. For almost every swinging driver out there, in the absence of mechanical/design issues or truly severe duty, 6 months works for everyone. If the mileage is longer ...they can use a synth.
For example, I went 9k/13 months (obviously short trip usage) on one of my rides. Well beyond either factory time/mileage recommendation. The Fe was a little high, as was the fuel dilution ...but the oil was 100% solid. I don't have the "after corrective action(s)" testing done yet ..but there's no need for me to fret over it in terms of long term wear.
Keep in mind that most domestically designed engines (non-Euro) typically spec only for dino oil of no distinction beyond the current spec (SM ..whatever). They plan for the masses for availability and consumer habits. Hence there's no distinction between synth ..dino ..Group II, Group II+, Group III, IV, blends ..etc.
I'll concede to the point that I've never heard of an engine failure due to too many oil changes.