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.

Hand calculated numbers, not trip computer data.

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.

06 Toyota Prius, had 04 Nissan 350Z; mom has 07 NAH

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.

06 Toyota Prius, had 04 Nissan 350Z; mom has 07 NAH