I finally got my oil analysis from balckstone today and decided to post. Please, let me know what you think. A little history about this car. I bought the car brand new on July 4th, 2008. I started keeping a detailed log of all maintenance on it as from 60,000 miles. I have done various kinds of oil change intervals on this car with this run being my longest ever at exactly 11,895 miles on the oil. This was my first and only time ever using and running 0W40 on this Maxima. I have a detailed thread about this car and here is the link... Detailed maintenance thread on my 2008 Nissan Maxima since brand new... Vehicle: 2008 Nissan Maxima Oil: Mobil 1 0W40 with Mobil 1 Extended performance filter. This is my first time ever using 0W40 on this car and my last. Just wanting to go back to Nissan recommendation of 5W30. Make up oil: 2 quarts Filters: Air filter and cabin filter has been on the car for about 20,000 miles now. Miles on Oil: 11,895 miles (I am rounding it up and saying I used the oil for 12,000 miles since it was short of exactly 115 miles to make it 12,000 miles done with this oil). Current miles on vehicle: 240,000 miles on car at the time of this oil change and getting the sample. All stock and all original parts since new. Car has 241,000 miles today as I am posting this. Why did I go so long? Because I had used 2 quarts of makeup oil, so why not push the car to the limit? Also, now that my car has 240,000 miles on odometer, I plan to be changing my oil every 10,000 miles. My car leaks oil so I do see myself using 2 quarts make up oil and so why not run it till 10,000 miles? Blackstone says I should do a 5,000 to 6,000 miles next time. I don't know, maybe I will still do 10,000 miles. The car has 241,000 miles on it, I am not really scared if it suddenly dies on me someday. The car has been very reliable and I still take it for round trip journeys over 1,000 miles. This time, when I changed my oil I decided to go back to what Nissan recommends for our car which is 5W30. I used Valvoline High mileage 5W30 with a K&N oil filter. I will stick with this for some time and will also change my QX back to 5W30.