I think I'm going to try pushing my Mobil 1 0W20 oil changes from 5500 to 7500miles between changes. My dealer has been recommending 5500, but seems like a lot of people go much longer, even in cold climates.

 

IIRC, the manual says 7500 miles, unless you're doing "premium" maintenance or schedule 1.

You might be wasting money w/5500 miles. Ever sent in samples to for analysis to places like http://www.blackstone-labs.com/ just to see how the oil looks... err tests after say 7500 miles?

I've done it for my former 04 Z after waiting a year between oil changes (VERY little mileage) and my Prius after waiting a few months longer than the 6 months, also due to putting on little mileage. The Z's oil turned out nowhere near as bad as I feared.

 

Oh, thanks cwerdna for that info. I have been basing my 7500 cycle on look and feel which while not the most accurate, after doing my own oil for so many cars raging from performance to clunkers, i am usually in the ballpark and err on side of caution. cephraim asked about this in another thread and I had no quantitative stats to back up my observations. ANyhow, would be good to know if anyone has gotten it tested. ..

 

I think it would be most useful if you got your own oil tested.

http://www.blackstone-labs.com/report-explanation.php has a sample report and explanation. High levels of certain elements can point to certain car problems.

Looking the UOA on my Z, I went about one year while putting only 1757 miles on the car during that time (car had ~52K miles on it). That's sort of why I wanted see what happened if skipped changing it at 6 months. The garage that I go to claimed their oil tends to test pretty well if I were to go beyond 6 months. But, when I brought in at the year mark, they were like... hmm, it's going to look really bad, I don't think you should bother getting it tested. I did anyway.