Didn't post much lately due to health issues (lower back pain - prayers and good vibes appreciated) but couldn't resist when I saw this curious bit (toyota fanboii beware
) While I don't agree with toyota's "poor engineering" LOL, the observations below ring true:
https://540ratblog.wordpress.com/"53. Are vehicles that call for 0W16 Motor Oil, well protected with such thin oil?
Below is a message I got from one of my Blog readers who is located in Greece, on that topic, along with my response. It is such important information, that it is worthy of its own Tech Article posted here. So, read on for the details.
Hi RAT,
3 months ago I purchased a Toyota RAV4 2.0L engine (dual port and direct injection) M20A-FKS (no hybrid) engine code (175hp) fwd. Toyota calls for, and filled it with, 0W16 viscosity motor oil. I did an effort and added an oil pressure gauge properly by a Toyota tuner garage engineer and the numbers are NOT satisfying and, of course much lower than the rule of thumb.
1000 rpm = 7.5 psi
2000 rpm = 13.0 psi
3000 rpm = 19.8 psi
4000 rpm = 28.5 psi
5000 rpm = 37.0 psi
6000 rpm = 43.4 psi
6400 rpm = 45.5 psi
I drained the Toyota filled 0W16 and poured in Amsoil Signature Series 0W30 oil a week ago. You want the numbers? Here they are:
1000 rpm = 9.6 psi
2000 rpm = 18.6 psi
3000 rpm = 27.0 psi
4000 rpm = 35.8 psi
5000 rpm = 46.5 psi
6000 rpm = 55.6 psi
6400 rpm = 57.5 psi
And, in fact, there was no observable change in fuel economy mpg values between the 0W16 and the 0W30 motor oils. I ordered two boxes of 0W30 Amsoil SS (24 qts in total). (Quaker State oil is not available in Europe).
To Toyota owners: Beware! It’s 90% possible that your engines that are filled with the called for 0W16 motor oil, don’t raise oil pressure to acceptable levels.
E.C.
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Hi again E.C.,
Thanks for sharing your data. That is excellent information for everyone to see, who uses that ridiculously thin 0W16 motor oil. NOTE: The ONLY reason Toyota calls for such overly thin oil, is their lame attempt to microscopically increase fuel mileage. But, they are making a mistake for doing that, because as you found out, which was already widely known, super thin oils do NOT improve fuel mileage at all, when put to the test in the real world. So, there is no good reason to use such dangerously thin motor oil.
It is the same thing with using overly thin 0W20 or 5W20 motor oils that are called for by some Auto Makers. Because those oils also do NOT increase fuel mileage in the real world. And the fact is, 0W30 or 5W30 are the optimum viscosity for most water-cooled engines. I do NOT recommend using any motor oil thinner than 0W30 or 5W30, if you care about protecting your engine. Keep in mind that 0W30 or 5W30 are BOTH rated as 30wt viscosity motor oils at normal hot operating temperature where an engine spends 99% of its life. 0W30 and 5W30 only vary in their cold rated viscosity, where 0W30 is a bit thinner than 5W30 when cold.
Just to be clear, the old rule of thumb for “HOT” oil pressure is: “Your engine should make at least 10 psi for every 1,000 rpm”. But, that is intended as a target for High Performance and Racing Engines.
Normal daily driver vehicles don’t need to adhere to that precisely. For them, the old rule of thumb is just an approximate general reference guideline, but not a hard requirement. If normal daily driver vehicles produce “anywhere near” the rule of thumb psi values, they should be fine.
But, your oil pressure data with the original super thin 0W16 Toyota motor oil is definitely “LOWER THAN IDEAL” for best engine protection, and is a cause for concern. Because that indicates the super thin 0W16 oil is bleeding off too quickly out of the bearing clearances throughout the engine, especially through the rod and main bearings. And with that condition, if the engine is subjected to severe loading, it could be at much higher risk of damage or outright failure. So, Toyota obviously doesn’t care about any of that, and are satisfied the oil only being good enough to barely get by in most cases. That way you will likely need another vehicle sooner rather than later. Shameful…
Your new higher oil pressure numbers with the 0W30 are MUCH BETTER, with an impressive average psi improvement across the rpm range of 31%, just from using the correct viscosity motor oil. And that shows that the ideal multi-viscosity 30wt motor oil is bleeding off through the engine’s bearing clearances, especially through the rod and main bearings, at perfectly desirable rate. That is proof that the engine SHOULD really be using a 30wt multi-viscosity motor oil, rather than that insanely thin 0W16 motor oil.
Toyota got it wrong……….again, which is no surprise. I have NEVER been impressed with Toyota Engineering. Because they do so many things wrong, or at least not as good as they should be done. Buyer beware!
That 0W16 Toyota motor oil also did NOT perform well in my Motor Oil Engineering Wear Protection Capability Test. It could only muster 84,295 psi, which ranked it a miserable 132nd out of 239 oils tested so far. It is highly unlikely that anyone would intentionally choose such a poor performing motor oil to use in their own engine.
BOTTOM LINE: Because of poor oil pressure, and poor wear protection capability with Toyota 0W16 motor oil, I do NOT recommend that anyone use that oil. Instead, I recommend that people select a Highly Ranked 0W30 or 5W30 from my Wear Protection Ranking List, and use that. Then their engine will be FAR BETTER protected than with that extremely thin and inadequate 0W16 factory motor oil.
Take care,
540 RAT"
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Top quality synthetic 0W-20 in winter and possibly 5W-30 in summer would be my choice, if I ever get something with an engine spec'd for 0W-16, that is in case the car is a keeper and not a lease.
