[JFP in PA]

Originally Posted by Blue-S

I came across a couple of resources recently that may shed some more light on the question of oil selection -- or perhaps simply throw gasoline on the fire! This link to the current Mobil 1 chart shows Zn and P levels for "SM" rated oils that roughly match the chart on LN Engineering's "Oil FAQ" page. Note also that Mobil 1 0w40 and 5w50 are claimed to carry more Zn and P than most other SM-rated Mobil 1 oils, but M1 15w50 is the Zn & P winner as far as Mobil 1 oils recommended for street-driven cars go. Check out M1 Racing 4T 10w40 -- it's SH rated.

http://www.mobil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf


The Lubrizol corporation - makers of various chemical products including components used in the manufacture of motor oils - has a really cool comparison tool. It allows the user to compare the performance of one (or more) oil specifications such as API "SM" vs ACEA A3/B4-04. That particular comparison is pretty illuminating, by the way! The king of the hill appears to be the Daimler MB299.51 specification, which is required in the Mercedes-Benz 3.0L V6 turbodiesel engine. Check it out:

http://sas-origin.onstreammedia.com/origin/lubrizol/EOACEA2009/RP/PC/index.html

Actually, I’ll stay with ACEA ratings (specifically A3, B3, B4) over any API rating or manufacturer’s internal specs. ACEA requires that the manufacturer submit the finished product for independent testing. Any formulation change and you have to resubmit to regain the rating. Under ACEA, there are no “approved” ingredients as there are under API; only fully tested and rated finished products

API has gone from being the petroleum industry watchdog and gatekeeper for specifications to becoming the public relations and lobbying arm of the industry. As the result, API specs are now “self policing”, which means the oil manufacturer’s determine what specs their products meet, how they are tested (if they are tested at all), and allow the substitution of components as well as reformulation with out retesting. The number of API specs themselves has grown to a ridiculous number, which have become so broad that they overlap and are hard to decipher.

Because of the lax API “self approval” process, you never really know exactly what you are buying; under ACEA you do. This is also why smaller oil blenders like Red Line and Royal Purple (amongst many others) carry no ACEA ratings; they are expensive and time consuming to obtain, and do not allow any formulation tom-foolery after approval……………