This is for all the people who ask about synthetic oil and oil change intervals. Everyone's car is different but I hope this will help some. Here's the info from my oil sample I sent to Blackstone. This was my first oil change after switching to Mobil 1 5w/30 full synthetic with 15k miles on my car. I got the oil changed wtih 3500 miles on it. I got the extra TBN to see how my oil is lasting. My numbers look really good. I am going to go 5k miles for my next oil change and see how it goes.

Some info on my car: 05 G35c 6MT, first oil change at 3750 mi. break in as suggested by the manufacturer (below 4k rpm for 1200 mi). oil changes as suggested by manufacturer. all oil changes up to 15k done at the dealer with their recommended oil grade. 15k service. I usually shift around 3k rpm for normal driving. I do push the car when I fee like it, and have redlined many many times. I have 19k miles and my rear tires are about to go. the first 10k miles were most city. roughly 7k miles are highway miles put on in the last 6 months.

Hope this helps.

 

I was gonna send my oil to them too, but last time dealer never took a sample and this time they told me I may have oil consumption problem, and want me to come back after 1000 miles.

 

Thanks for the post. I use Mobil 1 synthetic as well and usually changed mine between 3500-4000.

BTW, what filter do you use?

 

I had them analyze my first run with Mobil 1 as well...most city driving...they told me to push for 6000 miles. I'm gonna change it at about 5800 and see what they say.

 

I use the stock filter or whatever the dealer puts in. It may be the mobil1 filter.

 

Looks good. Also confirms that the stock Nissan filter does well in filtration. I need to send a sample in myself.