Originally Posted by R1000K3
0W40 is not thinner than 5W40, except for when the oil is cold and you want it to be thin. BTW, I use a 5W40 to
Acutally, i have heard over an over how it behaves less than a 40 weight when hot--something like a 35.
Originally Posted by vasillalov
I don't think a single sample will give you sufficient data to make a reasonable claim like that. HOWEVER, I do believe that you are on to something here. There are a BUNCH of oils out there that BMW has not had the time to test and certify for various reasons.
Finding a good oil is easy! Finding a GREAT oil for your engine is the tough part. Two things worry me about that oil sample:
1. Iron level. Too high at value of 10 ppm. I am used to seeing Iron level of 5 ppm out of Valvoline SynPower 5W-40
2. TBN. Too low at a value of 3.8. You should not accept anything below 5.0 TBN for a used oil. Valvoline SynPower 5W-40 TBN is 10 when poured fresh. One of the highest TBNs I've seen for widely available oils. Only Amsoil tops that with TBN of 11, if my memory serves me right.
I just want to make it clear that I am not trying to promote any specific brand of oil. I am only sharing my experiences with the forum as I've played a lot with oils and have done lots of analysis with BlackStone Labs.
Oils for diesel engines are specifically designed to hold and neutralize the soot that is inevitably a product of any diesel engine. I am not totally convinced that trapping those chemicals (from the soot) in the oil is good for our petrol engines.
I agree that a single sample won't be as good as multiple testing but it's a start. I also believe that it's a great start to compare to other oils like the castrol edge that I'm using right now.
Will you post your analysis so I can compare?
Remember that this oil was used extremely hard.
This was not used for a casual run to the store.
This was revved to 6500 rpm over and over for 4 20 minute sessions at Laguna seca.
You do bring up a good point with the soot though. I'm going to check with that but the last I looked, this oil IS
API SM, SJ, and SL approved, which is the same approval as the 0w40.