API Motor Oil Ratings Explained
Here’s betting that somewhere in your garage there’s a bottle or two of motor oil. Now, depending on how much of a keeper you are, this could range anywhere in age from a few weeks to decades! And when it comes to providing your car engine with what it needs to perform at its best, that oil really does play a major part.
API what?
The American Petroleum Institute (API) has been responsible for classifying motor oil since 1930. And it makes sense that as technology has advanced, so too has the oil we use in our engines.
Since 1930 there have been 12 different classifications of motor oil. The first of these was classified as SA, with further releases going up through the alphabet. The newest oils are the SN, brought out in 2011, and the SN Plus released in 2018. When it comes to an oil change, ensuring you choose the right API classification is essential.
All motor oils are not made equal
The thing is, the oldest API oils are not only considered obsolete but are also cause engine damage. These are rated as follows:
- SA
- SB
- SC
- SD
- SE
They were manufactured between 1930-1979 and should not be used at all as they will cause harm to the engine and its internal components.
API oils classified as SF, SG, and SH (produced between 1979-1996) are also considered obsolete, but not as harmful as their predecessors.
Motor oils from 1996 onwards
The oils produced from 1996 onwards are considered to be current. However… If you’re thinking, great! I can just use this newer oil, then sadly it’s not quite as simple as that.
SJ and SL oils are “reverse compatible” and can be used on older cars. In other words, they’re the ones that should be used in cars of more advanced years—ones with flat-topped camshafts—that would’ve originally needed the oils that are now obsolete.
But SM, SN, and SN plus oils (produced from 2004, 2011, and 2018 respectively) are not reverse compatible, and cannot be used in older cars. This is because they meet new EPA mandates to protect catalytic converters, with a much-reduced zinc content and a more aggressive detergent, calcium. 
Manufacturer recommendations
Confused? You’re certainly not the only one.
Even though oil bottles have the API rating displayed stating the category it’s easy to make mistakes. And never has this been more apparent than with a 2019 lawsuit filed against Dollar General for some of their motor oils on sale. These were classified as SA (now considered obsolete and harmful) and SF (obsolete). Despite the fact of the bottles sporting small print disclaimers many used them to harmful effect. The lawsuit is ongoing.
The easiest way to ensure that you use the correct oil in your car engine is to have it changed by the professionals. Jiffy Lube is a nationwide name that specializes in this very task. The Jiffy Lube near me and other locations use the correct API rating and only use the well-trusted, top brand of Penzoil. And of course, they always ensure strict adherence to car manufacturer recommendations.
With around 2,000 Jiffy Lube garages around the US, you can be guaranteed that whether you’re looking for an oil change in Naples Fl right across to Portland WA, their expert technicians have got you covered.
Find the nearest Jiffy Lube location here.
