BAD-HABIT

What do the API ratings mean on oil? I have Mobil 1 20w50 which reads sg,sh/cf JASO MA(what does JASO MA mean?). Mobil 1 15w50 reads sl,sj/cf and Valvoline 20w50 reads sl/sj........What do these mean and what ratings are better? Been wondering this for awhile now.

BH

Comanche3Six

Good question, I left my Rosetta stone on the job so I gotta guess it is a Mil-Spec.

Hydrocruiser

Before getting into all the confusion. They are simply Automotive gasoline and diesel engine warranty requirement ratings performed by the "Petroleum Institute". Automotive warranty ratings also take into consideration restricting an oil of what might do harm to catalytic converters
(by restricting ZDDP levels; restricting certain viscosities or levels of other additives). Also, some automotive manufacturers must use an "SL energy saving oil", as it was part of the requirements of meeting government fleet mileage averages. Not of much utility to "racing, severe service, offroad or high performance or motorcycle" applications. Remember "racing or "severe service" or "motorcycle" oils do not have to meet auto standards.


Now all the info:

Oil Service Rating

The oil service rating is a set of letters printed on the oil can to denote how well the oil will perform under operating conditions. The American Petroleum Institute (API) sets this performance standard. The API system for rating oil classifies oil according to its performance characteristics. The higher rated oils contain additives that provide maximum protection against rust, wear, oil oxidation, and thickening at high temperatures. The oil service ratings are as follows: 1. SA—adequate for utility engines subjected to light loads, moderate speeds, and clean conditions. Contains no additives. 2. SB—adequate for automotive use under favorable conditions (light loads, low speeds, and moderate temperatures) with relatively short oil change intervals. Generally offers only minimal protection to the engine against bearing scuffing, corrosion, and oil oxidation. 3. SC—meets oil warranty requirements for 1964 through 1967 automotive gasoline engines. 4. SD—meets oil warranty requirements for 1968 through 1970 automotive gasoline engines. Offers additional protection over SC oils that are necessary with the introduction of emission controls. 5. SE—meets oil warranty requirements for 1972 through 1979 automotive gasoline engines. Stricter emission requirements created the need for this detergent oil. 6. SF—meets oil warranty requirements for 1980 through 1988 automotive gasoline engines. The SF oil is designed to meet the demands of small, high-revving engines. A SF oil can be used in all automotive vehicles requiring detergent oil. 7. SG—meets oil warranty requirements for 1989 through present automotive gasoline engines. Contains more additives than SF oils. Can be used as CC or diesel type oils. It is a detergent oil. 8. CA—meets all requirements for naturally aspirated diesel engines operated on low sulfur fuel. 9. 10. 11. The CB—meets all requirements for naturally aspirated diesel engines operated on high sulfur fuel. CC—meets all requirements for lightly supercharged diesel engines. CD—meets all requirements for moderately supercharged diesel engines. operator's manual provides the service rating recommended for a specific vehicle. You can use a better service rating than recommended, but NEVER a lower service rating. A high service rating (SG, for example) can withstand higher temperatures and loads while still maintaining a lubricating film. It will have more oil additives to prevent oil oxidation, engine deposits, breakdown, foaming, and other problems.

A thicker oil will not meet a lot of current auto ratings and fuel economy is built into the equation. A lot of SL oils are thinner viscosity oils designed for high mileage and low emissions. You can buy a 99 cent/qt oil with an SL rating and an SG Mobil-1 20W-50 for $ 9.00/qt. Mobil-1 15W-50 has moly in it to increase economy and the 20W-50 dosen't. SL oils have to meet "certain economy energy saving criteria" Moly is not part of the oil's "wear inhibitor package". ZDDP is a wear inhibitor. Mobil-1 20W-50 has loads of ZDDP whereas Mobil-1 15W-50 does not because it clogs catalytic converters. That's why it's labeled non-auto or "motorcycle oil. "Racing oils" have very high ZDDP levels as they are not for "onroad use". ZDDP works!!

High performance motors want high ZDDP. In the case of Redline they use a ton of a different kind of moly instead with ZDDP.

In any event ZDDP and the "film strength" of premium "racing" synthetics are what makes them good not API ratings!!

Confused yet?

JASCO Japanese Ratings. Yuppers

Mercedes,Porsche and others have their unique own requirements.

Just remember. Oils costing less than a buck can be SL rated. Take it seriously but with a grain of salt if that makes sense.

jhnrckr

I think it is a Japanese standard, can't remember the exact acronym but it is on the bottle of Castrol Syntec.