Originally Posted By: Danh
Originally Posted By: BigD1
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That's why Havoline conventional 5w-20 has a different formula now because Havoline has always been very high in calcium. The product data sheet also lists magnesium too. This change might be great for the targeted turbo GDI engines, but I am not sure if it's a good thing for every thing else considering calcium has dropped from round about 2500 to 1900.
Magnesium and calcium perform the same function in motor oil, acting as detergents and counteracting acids. Magnesium is more expensive than calcium but also doesn't lead to the production of ash as a by-product. So, I'd say more magnesium and less calcium is a benefit to any engine, TGDI or not. Mobil1 products in particular substitute magnesium for calcium.
Yes, but TBN retention in Long drain intervals appears to be better in high Ca detergent oils, like Amzoil and the recent trends from competition, that is reverting back, becauss of this LSPI issues in turbed high cr cilinders. LSPI doesnt happen in Higher throttling because the injection system shoves a lot of fuel above 70%. The leaner maps are at lower rpms.