Hey guys, I ran Mobil 1 0w40 the past 2 years, this year I put on 6 full track days and about 2,000 total miles. I wanted to see if the race days wore out the oil. I had a regular analysis run with the TBN.
Looks like the oil was still in fine shape. FYI I change it in the fall before I put my car away, so the oil is about a year old, but only sees use from april to november weather permitting. It appears that changing the oil after every weekend of track is overkill.

 

Most people change their synthetic oil way too often. Good for you to test the oil instead of just following some arbitrary calendar to change it.

 

I think most of us would agree once a year with 6 track days and plenty of spirited driving is a good interval. This test shows it could probably last 2 years...
the viscosity breakdown I think is because i started the car, moved it onto my lift and shut it down. i usually heat it up fully before an oil change, but with the dry sump system, i don't think you need it to be hot. The quick on/off cycle probably left a bit of fuel in the oil...

 

I've sent my oil into blackstone a few times now and every time they've said looks great, you can extend your change interval. I don't blame people for short intervals but oil these days is pretty damn robust. I use Joe Gibbs 5-40 for reference. I dont track my car with any frequency but I don't exclusively drive around town either.