Yo G! wrote:Hi Guys,
Car engines are made way better than they were 35 years ago, when we changed oil more frequently. My G37's maximum oil change interval is 7,500 miles and that's what I do. It saves me $$ and still meets Infinity's warranty guidelines. I shake my head when I see you guys throwing away your $$. Save it for your child's Harvard education, I say!
While I change oil usually before about 4 k, I am doing so more out of insurance then out of need.
A study many moons ago on taxis indicated that with synthetic oil that they could go about 25k between full oil changes, however they did frequent filter changes. This of course means somewhere around 1 quart or so changed each time.
I figure one of the benefits in doing fairly frequent changes is that if any part gives up just a little bit of itself, that the frequent oil change will at least remove it from the system sooner than later, exposing the rest of the system for a much shorter time period. Consider external contamination as well. Say you drove down to the beach and kicked up a little sand and water and you had a dipstick not sealed in its slot. Changing oil would help catch this sooner.
I believe nearly anyone here probably could go much longer between changes and do changes as more of an insurance than out of necessity. Personally if I had a better place to work on the beast I would buy a bunch of filters and do frequent filter changes and follow a longer period between full oil changes while still satisfying Nissan recommendations which probably are partically based on the fact they will profit from a certain percentage of oil changes being done in their dealer shops using their products.
Perry