Originally Posted By: edyvw
Originally Posted By: loneryder
Here's my 2 cents. I have an 08 ML320 with the 642 diesel pre Blue additive. It requires 229.51 low saps oil. The only wgt that was ever available was 5-40. Then 5-30(229.52) was recommended strictly for café purposes I believe. I bought a bunch of Mobil 1 5-40 developed for MB when I heard they were going to quit making it. I have 1 oc left. I will switch to Valvoline 5-40 MST. Even though a 10k oci is recommended< I went 9k and sent a sample of the 5-40 for analysis. Iron was 60 and TBN was 2. I'm not comfortable with these numbers so I have gone to a 5-6k OIC. I believe that the 0/5-30 will allow excess wear. It's all about CAFE numbers for the manufacturers.
BTW. The local indy MB shop says 5-6k max OIC. He is an old guy who worked for MB for years and was their investigator for lawsuits that tried to blame MB for accidents etc. Go 10k with 0-30 at your own risks. The average MB owner doesn't keep their cars very long like a lot of us.
SO I use M1 5W30 ESP and got 24qt of Valvoline 5W40 MST on sale (use in sumemr).
Here is why 5W30 or 5W40 does not matter.
1. M1 5W30 ESP has cst of 12.2, while V 5W40 MST has 13.1. DO you really think that is big difference?
Also, more importantly, HTHS of M1 s 3.58cp, while V is 3.7. Not really significant difference. For example HTHS of M1 0W40 FS is 3.6.
2. This is why this 5W30 or 5W40 is irrelevant. In winter, my oil temp. on BMW is around 70 to 88c if I push. Cst is measured at 100c. So, actually for lubrication purposes in winter, 5W30 is better option. Most of the wear comes from cold starts and short trips, not minimal differences in oil thickness.
One thing is for sure, Valvoline is smoother then M1, but that is generally M1 deal, even in heavier oils.
I noticed one other thing that I am still monitoring.
When I was running Valvoline, my DPF regeneration cycle was approx. every 250-280km (I monitor that thru Carly). Since I switched to M1 it is every 470- 510km. M1 has SA level of 0.6, Valvoline of 0.79, and higher NOACK.
Still cannot pin point that that is 100% oil. I am switching between Shell, Conoco, Philips 66 to rule out diesel fuel as cause less frequent DPF regen. But next OCI I will use Valvoline again and check. I monitor all the time parameters.
I've noticed that intervals between regeneration shorten as oil ages. It starts with maybe every 350-450km and by the end of OCI it fells to every 200km. Probably as oil gets saturated with soot it can't handle combustion byproducts as well and thus filter gets clogged more often.