2nd oil report

[Fred]

Ok I did my 2nd oil report, oil was 10w30 Royal Purple. Engine had 85,300 miles at the sample. Oil had 5,160. The tbn was 2.0, the oil read more like a 5w30 than a 10w30 in viscosity, though it wasn't due to any fuel so they aren't worried. Copper is still too high and they don't see any obvious cause of it. New gm v8's and 6's tend to leave copper high in the oil up to 50,000 miles, but it should probably not read at this level after that. The extra quart of oil use add should not hurt anything. Try 6,000 miles on the next oil. We'll watch copper.

aluminum 2
chromium 1
iron 14
copper 46
lead 1
molybdenum 111
nickel 0
manganese 1
silver 0
titanium 0
potassium 5
boron 0
silicon 11
sodium 13
calcium 1732
magnesium 1082
phosphorus 743
zinc 880
barium 0
sus viscosity at 210f 57.5, fuel % <0.5%, antifreeze % 0, water % 0, insolubles % 0.3.

[CDNFB]

Re: 2nd oil report

Cool stuff, but I have questions.

Is 6,000 miles the recommended interval?

What is the mileage that the base numbers for comparison were established?

What are the base number (or expected average) for each of those items?

[Fred]

Re: 2nd oil report

They only one they are worried about is copper. On my previous oil sample I went 4700 miles on it. Royal Purple actually recommends oil change intervals of 12,000 miles. Here are the universal averages.
aluminum 3
chromium 1
iron 13
copper 18
lead 7
molybdenum 53
nickel 0
manganese 0
silver 0
titanium 0
potassium 8
boron 47
silicon 11
sodium 13
calcium 2082
magnesium 114
phosphorus 712
zinc 864
barium 0

[CDNFB]

Re: 2nd oil report

OK, those are the universal numbers, but for what mileage? If I go 3000 miles and sample the oil the numbers would be lower than if I go 12,000 miles right?

[Fred]

Re: 2nd oil report

In most cases yes unless there is something wrong with your engine internally that is wearing out.