3 Quick Tips To Choosing The Right Oil For Your Toyota Prius

I want to put in a disclaimer here and say up front that I am in no way telling you what oil to put in your Prius. I also have been researching engine oil for the last 7 years. I have poured my soul into finding a simple, non confusing way to help people know how to choose what oil is “right” for their car and more specifically, your Prius. Hopefully, this is simple and not confusing.

API, ACEA, JASO, ILSAC

All of the acronyms probably make zero sense to you, and that is okay. The only thing you need to know here is which one you need to pay attention to and why.

API or the American Petroleum Institute is the governing body that sets forth the service classification that certifies non OEM engine oils for use in vehicles that require a certain classification. For example 2010 Toyota Prius requires an API service rating of SN. The “S” stands for spark ignition engines and the “N” is the latest classification of engine oil, or the most modern formulation to date. If your vehicle was built and set to run in the United States then use this rating to find what you need.

ACEA or the European Automobile Manufacturers Association (as if europe was not already screwed up enough) have their own classification of engine oils for gasoline and diesel vehicles. Classifications you could see would be C3-10. This particular classification would be a Top Tier low SAPS (sulphated ash, phosphorus and sulphur) that is for use in high performance and diesel engines. So unless your Prius is a high performance euro model, do not pay attention to this.

JASO or Japanese Automotive Standards Organization is specific to Japan. They are the governing body that sets for regulations just like the above mentioned organizations. An example of a JASO oil classification would be either JASO M (two stroke) or JASO F (four stroke) classifications. Neither of which are in use for automotive but motorcycles. JASO 4T specs are for automotive applications and carries a high content of friction modifiers (do not worry about what this is just know modern engines need it). For Prius even though it was built in Japan, it may have a different standard depending on where it ends up in the world. This is why ILSAC is with us today.

ILSAC or the International Lubricants Standardization and Approval Committee, is an organization that is a joint effort between the U.S. and Japan to have the same level of oil certification so that cars I.E. the Toyota Prius can be built in Japan and driven in the U.S. They can have access to the proper engine oil as well. A current ILSAC rating would be GF-5 . What GF stands for still remains a mystery to me today (and I will give you a buffalo nickel if you can tell me). If I had to wager an educated guess I would say gasoline, four stroke, classification 5. I have yet to get clear feed back on this.

Overall, read your owner's manual and if you Prius says API service SL but you cannot find that, it is ok to use the latest API service rating which is SN. API ratings are backwards compatible. This means that as oil technology advances, your current rating gets upgraded to a better oil than what came in it standard.

Just make sure what you are choosing meets the minimum requirement of API for your Prius. Especially if you a DIY person like myself.

SAE Grade 5w30, 0W20

Society of Automotive Engineers (SAE) Viscosity grading. Ok, here is what you need to know. Put in what the vehicle calls for. Also the “W” stands for winter, not weight (please do not make me correct you on this, it is a huge pet peeve of mine).

This oil is called multi viscosity oil and is designed to act like a lower viscosity oil when cold and a more viscous oil when it is warmed up. There is some serious science in this, just know that is what it does. So, if your Prius is calling for a 0w16 engine oil, that is what you put in it. If it calls for a 5w30, that is what you put in it. Get the picture? This is not rocket science, except to those who actually made the oil, that is kind of rocket science. You just not need to be worried about that. Do what is required and everything will work out. Promise my black little heart on it, and for heaven’s sake avoid putting the wrong stuff in.

Oil Manufacturers

Did you know that there are only a handful of oil companies in the world? Then why are there so many brands of oil? Marketing. Just like Toyota has done a great job with marketing Prius, oil companies also want your money. In fact they will tell you that Mobil 1 is the best motor on the planet for all sorts of reasons. Then Valvoline will step in and tell you the same thing, about why they are better than Mobil. Then you have companies such as Royal Purple, Kendall, Pennzoil, Wal-Mart Super Tech and a billion others tell you the exact same thing.

Here is the filthy secret that no one tells you and why you feel better about yourself after spending way too much money on oil. Essentially they are all the same. The differences come in the additive packages that are put in them. One is more like chocolate cake, another is a yellow cake, and another is a lemon cake. They are all cake, just with different ingredients. Choose one that meets the needs of you car.

There is a massive undertaking when it comes to knowing all I know about engine oil, and for me I use a house brand NAPA synthetic for my Prius. I know who makes it and why it is cheaper than the competitor. So for all you reading this here is how you choose the best oil for your Prius.

1. Does it meet the API, ILSAC, JASO or ACEA standard (depending on what country you are in)? Yes? Okay go to step
2. Does it meet the requirement of proper viscosity your Prius needs? Yes? Go to step 3.
3. Is it on sale? Or is it cheaper than the big brand name oil it is sitting next to? Yes? Buy it. Save Big.

Literally, you cannot go wrong if the oil meets the standards that are set forth by Toyota. I will not get into structure of engine oil, base stocks and additives right now. However, if the demand for another article is needed to do a deeper dive into oil, I will gladly take the reins. For now use the guide above change it on time as per Toyota requirements and save yourself the extra money. Take the significant other out for milkshake with all that green you saved today knowing you are now one step closer to being a master tech.

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Peter Neilson is an automotive consultant specializing in electric cars and hybrid battery technologies. He is an automotive technology instructor at Columbia Basin College. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter can be reached on Linkedin and at Certified Consulting and on Twitter at @the_hybrid_guy. He is also ASE Certified.