Originally Posted By: BigJohn
If most of the new diesels released in 2016 require low ash rated motor oil and if most of them have particulate filters and require AdBlu, etc.....
What the heck is the difference?
One vehicle demands 0.7 ash or lower....and other is fine on Rotella 5w40.....1.0.
Are the differences enough that it will cause system failure...using Rotella?
Difference is in EGR, DPF itself and regeneration process. BMW and Mercedes are usually OK with higher ash levels, and require Mid-SAPS oils. VW is very strict on ash level. This is not 2016 models, low ash oils are present in diesels last 10 years. Most commercial engines require Mid-SAPS oils.
SO what happens if you use Rotella T6 in engine that requires lower ash content? Nothing immediately, but DPF will get clogged faster, meaning regeneration will occur more often and will not be able to clean DPF as well as before. On top of that, your mpg will get worse bcs of more often regeneration and bcs DPF is getting clogged.
For example, my BMW requires BMW LL-04 spec which is Mid-SAPS specification. I use M1 5W30 ESP which has lowest SAPS level of any C3 oil available on the US market. Actually, I saw increase in MPG compare to OEM oil, probably because regeneration is not as often as before.
