Nissan is always changing their oil change intervals; I've seen it bounce back and forth between 3750 and 7500 miles over the years and then the 5000 mile interval came into play. I've been using Supertech 5W30 Full-synthetic in my vehicle for well over a decade at 7500 intervals and no issues. I've even had my R51's oil analyzed by Blackstone Labs with 7500 and 12000 mile samples (engines with 150,000+ miles on it in both cases) and the results were great! They stated on the 7500 sample that I could extend oil changes to 9500 miles. On the 12000 miles sample, they said it looked great but my TBN number was 0, meaning that the additive package had been spent and it was time to change the oil; the 12000 miles was a result of not being able to get the oil changed at the time and I still follow my 7500 mile intervals, today. Other than replacing the timing chains on both of the VQ40DE engines (which was a manufacturer defect rather than an issue caused my maintenance), both of my engines are still running strong and quiet with 217,000 and 270,000 miles, respectively, and don't burn any noticeable amount of oil between oil changes. At $16/5-quart jug, I don't see any reason to change oil brand at this point. FYI, I use only Nissan or Purolator Pure One oil filters.