Quote:
Originally Posted by Chilled
Quote:
Originally Posted by edycol
So reasons for less calcium is IMO LSPI prevention. High calcium content in the oil can create perfect environment for LSPI event. That is now biggest worry with small turbo engines and 8-10 gears automatics where engine is usually in highest gear, low rpms, and then there is sudden demand for power. In large engines (pretty much 2.0ltr and up, although there are some 2.0ltr engines that experience this) is non issue. But there are a lot of small turbo engines.
I think that is what is driving Castrol to use less calcium. They also gave up on titanium. I think it was an issue titanium not mixing well with magnesium.
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Cheers, So for us its not really a issue/concern. So something with a higher Calcium and a lower Magnesium rating would be better.
What about the mix of Zinc and Phosphorus? I think i saw somewhere, (maybe here) say that Zin should in around 800-1000ppm, range. Looked over at the air-cooled (no idea on difference), Porsche guys, and they all say 1200ppm as the minimum? |
Magnesium or calcium etc. it is choice of blenders what to use. There is no definite answer which is better. What matters is how these additives "cooperate" with each other and ZDDP which is basically acidic. Detergents are acidic neutralizing additives while ZDDP is basically ester acidic additive. It is contradictory. But, they must work together in harmony. When blender choses more of certain additive there is reason for it not necessary related to wear protection or cleaning but more how it works with other stuff.
ZDDP is the most important wear protection additive. Once hydrodynamic lubrication is not sufficient (HTHS) ZDDP creates protective film. This is usually case around piston rings not so much rod bearings (that should never happen there). But too much ZDDP can be bad. ZDDP is corrosive and acidic. It is bad for catalytic converters. So, if blender let's say choses 950ppm of Zinc over 1,000ppm that is bcs. synergy between all those chemical components. That is why additives are bad choice as they mess that up.
Air cooled engines, flat tappet engines etc. like a lot of ZDDP. You have to take into consideration that engines and materials used made progress over the years. But just bcs. it is good in air cooled Porsche, doesn't mean it is good in other engines.
Hence approvals. You stick to those I mentioned above, and chose best oil among them. Approvals are there so people don't guess what to use. These forums are different as people are enthusiasts etc. but for general public approval is the most important thing.