Originally Posted By: OVERKILL
Originally Posted By: stchman
Originally Posted By: OVERKILL
Originally Posted By: stchman
Many folks that own BMWs use Mobil 1 5W-30 in their cars and just change the oil out a little more frequently.
Which just reeks of ignorance since the cars spec an oil with a much higher HTHS, not just a longer drain capability. The Euro oils also have higher levels of AW additives.
I am not a BMW expert, will a BMW engine last longer with Euro oil(5W-40) changed at 15K than Mobil 1 5W-30 changed at 7500? I say no, but if yes, is there any kind of proof?
It isn't just the OCI length but rather also the higher levels of AW additives and higher HTHS of oils like M1 0w-40, PU 5w-40...etc that meet the LL-01 specification that BMW calls for. The OEM test sequences are more demanding than your generic API ones.
You effectively reduce the minimum film thickness in the engine by runner a thinner, non-spec oil and yes, that could certainly lead to a shorter engine life if the engine is pushed and oil temperatures elevated. Is it likely with typical North American driving conditions? No, but it is still possible. Also, BMW has reduced the OCI length to 10,000 miles now.
The entire premise makes no sense anyways because M1 0w-40, which is approved, is no more expensive than the thinner non-approved M1 5w-30.
True, Mobil 1 0W-40 is available at Walmart for the same price as Mobil 1 5W-30.
0W-40, 0W-30, 5W-40, or 5W-30 are all approved viscosities for BMW engines.