Higher Lead then Iron? Thicker Oil?

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Jul 8, 2002
Lake Anna, VA
These are the last two analysis' on my mother's Monte Carlo. I've read on here before that when your lead number is higher than your iron that is a sign your engine might need a thicker oil to protect the bearings? Her 3.8L now has 92000 miles and runs perfectly but I was thinking on going with Schaeffer's 15W-40 PAO Blend on the next interval to see if the lead number drops.

1998 Chevrolet Monte Carlo Z34 3.8L
Schaeffer 10W-30 PAO Blend
4,130 miles on oil
87,127 Miles on Engine
Oversize Wix oil Filter 51036
K@N Panel Air Filter

Car is driven everyday around 50 interstate miles.

1st number is new analysis 2nd number is previous sample same interval only with M1 10W-30


Aluminum 4 4
Chromium 0 1
Iron 7 15
Copper 18 17
lead 12 6
Tin 0 2
Molybdenum 88 63
Nickel 0 0
Manganese 0 0
Silver 0 0
Titanium 0 0
Potassium 9 34
Boron 8 120
Silicon 9 9
Sodium 11 9
Calcium 2147 2822
Magnesium 7 41
Phosphorus 809 814
Zinc 973 1036
Barium 1 1
SUS Viscosity= 60.5 59.2
Flashpoint in deg.F=415 425
Fule-0.5 .5
Antifreeze=0.0 0
Water=0.0 0
Insolubles%0.5 0.4
TBN= 2.6 5 -Old Method

I did do an AutoRx flush before the run with Schaeffer's oil above. Could the AutoRX cleaning cause the higher insolubles and lead count? Any opinions on what to do?
there are many more variables. Cleaning with AutoRX could also change the numbers. Neither is bad. If you put them alongside the 62 I got back this morning you are definitely in the best 10% with either sample. Your copper is of more concern than the iron.
Uconn1150...Up until I got ahold of it at 70,000 miles it had Pennz 10W-30 and Purolator filter courtesy of the local quickie lube. I then ran two intervals of M1 Supersyn 10W-30 then the AutoRx flush then went to Schaeffer's which is what i'm currently running. I also noticed the high copper but it seems these 3.8's always show high teen copper numbers.

Originally posted by Ryan00TJ:
... Could the AutoRX cleaning cause the higher insolubles and lead count? ...

Highly probable since you are on the "rinse" cycle. Doubt you need thicker.
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