엔진오일 관련 용어들(ACEA, API, SAE, HTHS, FE+ 등등)

 

(비머월드닷컴 에서 펌)

Engine Oil Info for BMW

Terminology & Acronyms

Below are some explanation of the scientific terminology, jargon, and acronyms commonly used when discussing BMW engine oil.

ACEA	Association of Constructors of European Automobiles. Rates and grades the quality of motor oil according to their own specifications. For gasoline BMWs, the ACEA rating should be A3/B3 or higher.
API	American Petroleum Institute. Rates and grades the quality of motor oil according to their own specifications. If you look at a bottle of oil it will have a "API XX" stamp. As new oil formulations are announced the rating gets progressively "higher" - SJ, SM, SN, SN Plus, SP, etc. For gasoline BMWs, the API rating should be SJ or higher. You can use the API rating to judge how appropriate the oil is for your needs. SJ is an older spec and will have more ZDDP and additives that make it a "better" oil (in our minds). The newer SP and SN formulations will be focused on fuel economy and emissions. These are not "bad" oils and may be fine for daily use. But look elsewhere if you want a better oil for your needs. API also has Diesel oil ratings that use different labels but with similar meanings. Current specs are CK-4 for 2017 or CJ-4 for 2010 or CI-4 for 2002. The "4" in the label refers to a 4-stroke engine so stay away from any Diesel oil with a "-2" rating. Diesel oil can be used in gasoline cars but there are restrictions. See Diesel oil paragraph above.
Diesel	A type of internal combustion engine that uses extremely high levels of compression instead of a spark plug to ignite the air/fuel mixture. A capital "D" is the correct spelling as the engine technology was patented by Rudolf Diesel.
Base Stock	Base Stock is the material that oil starts from - petroleum-based or true synthetic. All oil is classified under one of five Groups, I-V. Groups IV and V are full synthetic and have no petroleum base. They use synthetics that are more resistant to heat and stress than petroleum-based oil. High Performance and Racing oil are almost always Group IV or V. Groups I, II, III are all petroleum-based with III being the highest quality. All BMW-approved oils are Group III yet are still marketed as synthetic oils. This is to avoid confusion with the different base stocks of Group IV (PAO) and V (ester). Any oil brand that wishes to be approved by BMW must be a Group III base stock. So it's common to see premium high performance oil that is better than BMW oil but does not have BMW approval. Red Line Oil encountered this with their own High Performance oil that could not be BMW approved due to their Group IV and V base stock. They had to formulate a different oil with a Group III base to get the BMW approval (Red Line Professional Series). This oil actually performs worse than their High Performance oil in laboratory tests but carries the BMW stamp of approval.
Dino Oil	You may see references to this, especially on oil-focused message boards. Dino oil is non-synthetic, petroleum-based oil from dinosaurs. Dino/petroleum oil lacks the same additives and detergents of modern synthetic oils so it has fallen out of favor, except in the vintage car community.
FE or FE+	Fuel Economy and Fuel Economy Plus. Oils with additives that allow a lower viscosity for better fuel mileage. The additives have similar protective properties as thicker oils but allow a thinner viscosity.
HDEO	Heavy Duty Engine Oil (sometimes with Diesel in the name). Extra thick and with additives that make it well suited for older or high mileage engines with “loose” production tolerances. These oils tend to run thicker than others so more wear and noise is to be expected on cold starts and fuel mileage may decrease slightly. The additives trap and contain dirt and foreign particles better than a straight passenger car oil. This is common oil in Diesel engines in dirty environments - farms and construction sites.
HTHS	High Temperature / High Shear conditions. This is used to pinpoint areas in the engine that have high temperatures and friction and the oil is at risk of “shearing” or breaking down (camshaft and valve lifter surfaces, for example). A higher HTHS grade means the oil is more resistant to shearing in these conditions. However, a lower HTHS is desired for efficiency. It is expressed in centipoise (cP), a unit of viscosity. Until c.2014 BMW specified a HTHS of 3.5cP. The latest LL-14 spec fuel efficient oil has a cP of  2.6-2.9; for comparison, water has a 0.899cP. For high performance and track use we want a oil that stays thicker, not thinner.
LL	Longlife. BMW’s name for oils that are approved for extended oil change intervals.
NOACK	A grade for how much oil is lost due to evaporation. The thinner portions of oil evaporate first, leaving behind a thicker fluid. An oil that is more resistance to evaporation will hold up better at higher operating temps. The higher the number the more fluid is evaporating. Really high quality oil will have a low NOACK value.
OCI	Oil Change Interval, or how often you change your oil. BimmerWorld recommends an OCI of 5,000 miles for street cars and more often for track/racing cars.
Racing Oil	Oil sold for off-road and racing use is not subject to the same regulations and approvals as standard passenger car oils. Race cars also do not tend to have catalytic converters, therefore, oil manufacturers do not have to engineer their racing oils for fuel economy or emissions. Also, race cars tend to have much more frequent oil changes so there is no need for extra detergents. Racing oils are not very well suited for street cars.
SAE	Society of Automotive Engineers, responsible for setting the oil viscosity grades.
SAPS	Sulfated Ash, Phosphorus, and Sulfur. Newer oils have a low SAPS value - the levels of these materials is low which is good for the environment and the catalytic converters. However, to get low SAPS more synthetic additives are required which have less protection, especially in higher operating temps. Low SAPS oils are common for Direct Injection engines (see section above).
TBN	Total Base Number is a grade for the amount of active additive left in used oil. This will be displayed in a UOA and gives an indication of how “used up” the oil is and if the owner can safely extend the OCI further. Fresh oil starts out with a TBN between 6.0-14.0 depending on type. A well-worn oil will have a TBN of 1.0.
UOA	Used Oil Analysis, recommended to determine the performance of motor oil and assess internal engine wear. UOA is especially important for S54, S62, S65, and S85 M engines to evaluate rod bearing wear.
Viscosity	The rating for the internal friction of fluid dependent on temperature. The SAE assigns the grade based on two temperature standards: cold (the “W” in 5W40) and high (100*C). The higher the number, the thicker the oil is and the longer it will take to reach operating temperature. The thicker oil also has more resistance on moving parts, which is why BMW has recently adopted low friction 5W and 0W oils to reduce cold start friction and improve efficiency. In addition to the familiar SAE grades, viscosity is expressed in centiStoke units (1 cSt = 1 mm2/s) and measured at two different temperatures - 40*C and 100*C. A higher cSt is a thicker oil, giving more protection but less efficiency. However, a low viscosity does not automatically mean less protection (the chemical makeup of the oil determines that).
ZDDP	Zinc-Dialkyl-Dithiophosphate, a metallic additive in older engine formulations. ZDDP has anti-wear properties that have been replaced with synthetic additives because of environmental reasons. Higher ZDDP is also bad for modern catalytic converters if poor ring seal allows oil into the combustion chamber. However, the great advantage of higher ZDDP is that it bonds to the surfaces and provides excellent lubrication even at high temps. This is great for higher mileage engines with loose tolerances - the extra ZDDP helps fill the gaps that were not there when the engine was new. High ZDDP oils will also tend to have high HTHS ratings, making them attractive in high performance engines, especially tuned turbo engines. Environmental regulations required oil manufacturers to reduce ZDDP levels in gasoline oil. However, Diesel oil still contains high ZDDP levels which is why you will often hear engine builders and enthusiasts recommending it. However, don’t just grab oil with the highest ZDDP or straight Diesel oil. A high ZDDP must match the API and ACEA ratings for your BMW.