Mobil 10w40 HM (SN) // 3,379mi OCI // 2002 BMW 525

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Nov 5, 2010
Akron, OH
Below is my third UOA for this vehicle; the second with M1 10w40 HM. The first was with SM, this is SN. The ad-packs differ slightly, but the results were the same. Good wear numbers and it was still a 40-weight when removed. Nothing too exciting here, but it's another data point. I refilled with M1 0w40 for the winter months. (All values not shown are < 5 ppm) Iron - 11 Moly - 73 Boron - 72 Calcium 1549 Magnesium - 533 Phos - 853 Zinc - 945 kV@100C - 13.56 cSt Flashpoint - 400F Fuel - < 0.5% Insoluables - 0.3%
Originally Posted By: dparm
I'd be inclined to run the 0w40 year-round.
+1 and on a longer OCI...
Two reasons for the short OCI (1) I've owned this car less than a year and believe the previous owner probably went over 15k for OCIs, and (2) the weather is getting colder, so I took advantage of a recent warm weekend to change the oil. I'm using HM in the warmer months to see if it helps my oil leaks (vanos lines, filter housing). It didn't. I have 12qts of M1 10w40 HM SL in the garage, so I'll go back to it next spring.
I think the SL M1 10W40HM seemed to run smoother,but it may be all in my head. The SN has a lowered zddp level also.
Originally Posted By: Matt_N
I'm using HM in the warmer months to see if it helps my oil leaks (vanos lines, filter housing). It didn't.
That's too bad. I was thinking of giving it a try in hopes of reducing my leaks as well.
It is too bad HM couldn't help the leaks, but I think they're beyond the help of what oil can do. Still, it's worth a try in your motor.
Originally Posted By: JAG
I hear about leaks in BMW engines fairly often. Do they use [censored] gaskets that don't last?
For the most part, yes. I had my valve cover gasket replaced at 45K miles because it was leaking. Then I had my oil filter housing gasket replaced at 62K. Now at 78K I think it's the oil pan gasket that seeping a bit... nothing major though... just a few drops of oil on the garage floor now and then.
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