My first oil analysis at 40,000 miles running synthetic.

That's why I plan to OA every 20K miles.
I mean its $30, so even if I only went to 80K it seems like I would be in the good, as long as the oil is still good at that time.

Never heard of the sentinel system.

Many years ago before oil bypass were built in they use to sell them with the promise of million mile oil changes.
I am not sure if oil that is used, is less efficient than oil that is new, at least in synthetics.
Paccar recommends 75K change intervals.

Normal Duty (Line Haul) – less than 20% idle time 75,000 miles (120,000 km) 2,250 hours or 12 months

 

Correct me if I am wrong but sulfur from high sulfur diesel fuels made the oil more acidic over time?

 

For conventional $3xx yes.
In a year when a 3500 profit week is a good week for me, I try to cut costs where I can, safely.

 

Several different ways it woukd interact with the engine, and oil over time. But it would affect lubricity.

Overall, moden engines are much better. And todays fuels and oils make extended intervals possible. But IMO, not worth chasing the dimes for an OO.

 

I'm using the 15-40 Mobil synthetic at around 50$ per 2.5 gallon. Roughly 225$ with tax. Are you changing your own oil?

 

An engine with that many miles and showing aluminum so high I dont think I would go over 40k miles to an oil change. Unless I was looking to destroy an engine in 2 years.

 

Does more than twice the average metals sound like something is breaking apart?

 

You needed to do an OA at the recommended oil change intervals, like 15k or 24k, this will give you a baseline going forward and see changes as they are made. in your case maybe 10k the first time and then 20k.

 

No, don't have the stuff to do the change, and I can't fit under the fuel tanks or bumper.
Would cost me roughly $500 for the stuff I need to self change it, plus having to dispose of the oil.

 

I am wondering if this was because I took the sample from the oil filter housing. Maybe some backwash coming off the filter that wasn't trapped.
I want to get an oil pump, to get some out the dipstick.