a chance to compare M1 0w40 with 0w20. the latter had 1 quart of makeup and was a qt low when the oil was changed and the sample taken. the 0w40 had a 1/4 qt of makeup. doesn't look like the lighter vis had any effect on wear at all. TBN was very good for an oil that isn't considered a long life oil.
Code:
OIL M1 0w20 M1 0w40 MILES IN USE 10046 9892 MILES 125.7k 115.7k SAMPLE TAKEN ALUMINUM 4 3 CHROMIUM 1 2 IRON 23 23 COPPER 3 5 LEAD 1 1 TIN 0 0 MOLYBDENUM 101 92 NICKEL 0 0 MANGANESE 0 0 SILVER 0 0 TITANIUM 0 0 POTASSIUM 2 2 BORON 52 114 SILICON 21 18 SODIUM 7 7 CALCIUM 2434 3049 MAGNESIUM 13 18 PHOSPHORUS 619 878 ZINC 768 1117 BARIUM 0 0 INSOLUBLES 0.4 0.5 WATER 0 0 FLASHPOINT ºF 400 385 SUS VIS 210ºF 53.5 71.2 cSt @ 212ºF 12.11 12.33 TBN 2.5 2.0