Oil change interval

The oil analysis you had done at Speedco was useless and probably misleading. The personnel who take the sample don't have the training or motivation to get an uncontaminated sample. The desktop machine probably is not maintained properly and is also operated by the same under trained people.
Get a sample properly taken following the recommendations of any of the major laboratories that do them. You can get sample kits from Cummins. Do samples at the next several oil changes. The lab technicians who run your sample will be able to give you better and better opinions about the condition of your engine after several samples and a history is developed.
One sample taken even under the best of conditions is not going to give you much insight into the condition and oil change interval.

 

Oil changes are relatively cheap, why try to stretch it out to the limit? I do mine every 10-12k miles. I make around 25k with those miles so why try and squeeze an extra 5k miles out of a $300 oil change?

 

Sounds a lot like my magician (mechanic).

 

My Volvo Manual recommends that oil changes be done by 45,000 miles. In order to not screw with the warranty, it has to be done by then.

Of course I don't actually plan on waiting every 45,000 miles but probably every 6 weeks, 15-20k miles.

 

So much more to that story then just oil.

 

Last company that i drove for changed the oil and lubed every 12k miles. I was driving an 07 Acert with 906k on the clock when I left. The only time we were under 80k was empty.

 

Rotary oilfilter?

 

Don't know what you mean. Just the standard spin on type.

 

I get oil changed every 35k miles on my assigned 2016 volvo with isx15. Mostly because of light loads.