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- Oct 22, 2018
- Reaction score
The report in post#1 shows that the oil didn't shear.I don't know enough about an OCA to determine what is good or bad, but I'm curious why you chose a 20wt oil for a 180K motor over the OE spec 30 wt?
Does the manual say a 20wt is ok for that year engine?
I know Amsoil is good stuff, I'm just thinking on the shear over time by beginning with a 20wt oil over a 30wt.
AWD and always properly inflated which helps me achieve the great reliability and gas mileage.Is your Yukon AWD or RWD? Tires properly inflated?
as I stated in post#1 I changed all 4 recentlyNew upstream O2 sensors over worn sensors can play a part with fuel economy.
I'm a light aircraft owner (25+ yrs) and a retired pro pilot.Another thought, if you compare highway MPG in the dead of winter as opposed to spring/summer, I agree, wind plays a big part. Cold, dense air is harder to push through, if you have flown light planes you know what I mean.
Iron was much higher in reports 3, 4, & 5 when I was running 5w-30, but as I stated in post#1, there was an overheat event due to a broken heater hose T fitting shortly before sample#5 was submitted for analysis.Overall it looks good, but if the iron is up over your other oil changes, what comes to mind is also the crankshaft journal, along with the before mentioned cylinder sleeve.
Again, above my pay grade, by personal thought is to stay with a 30wt...but that's just me.
I learned on BITOG forum how thinner viscosity oil can flow a higher volume thus doing an arguably better job of carrying heat away and lubricating.
Like I said in post#1 = I drive conservately, I don't tow or hotrod.
I'm not certain what my next oil change will be with.