BTW:
here's my latest oil analysis using Schaeffer's 15w-40 Supreme 7000 Semi-synthetic HDEO oil:

http://theoildrop.server101.com/forums/showflat.php?Cat=0&Number=231281&an=0&page=0#Post231281

I'd like to see almost any Mobil 1 beat it. . .

:-) neil

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1988 Mercedes C36-powered 300TE wagon
199K miles
65K miles on engine

Interval: 6,500 mostly city miles (6-months), with oil filter replaced after 3-months.

Head gasket & valve stem seals replaced about 3-years ago.

Looks like ONLY TWO oil-changes per year now!

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SCHAEFFER'S OIL ANALYSIS: 7-9-07

Wear Metals (PPM)
Copper: 3 (previous 7)
Iron: 13 (24)
Chromium: 1 (2)
Aluminum: 3 (7)
Lead: 4 (4)

Additives (PPM)
Moly: 242 (147)
Phosphorus: 1555 (1929)
Zinc: 1706 (2048)
Magnesium: 14 (39)
Calcium: 4153 (5380)
Sodium: 0 (0)
Postassium: 0 (0)

Contaminents:
0% anti-freeze
0% fuel-dilution
Silicon: (4) 11

Oil Properties:
Viscosity: 13.80 (15.22)
SAE: 40W (40W)
Sulfur: 10 (16)
Oxidation: 11 (4)
Nitration: 10 (7)
CONTAMINATION AND ADDITIVE DEPLETION LEVELS NORMAL.
MAINTAIN CURRENT OIL DRAIN INTERVAL