Oil experts, please share your knowledge.

[Shel_B]

Here's another opinion about thinner oils. Jason is pretty well regarded, and has a connection with Mobil. I didn't read this entire thread as I've read enough of such discussions to have a good idea of the content. So, this link is for @Dimitrius James.

 

[Carlostrece]

Regarding OP post #1... I'd use 5w20 if I had a Rav4. That's what my neighbor has in her CRV and it works well for her. i.e. - I'd go a bit thicker than 0w16, but not too much thicker. That's my opinion.

 

[Carlostrece]

I just bought 5w20 Quaker State High Mileage Full Syn for my neighbors 03 Honda CR-V. That oils runs slightly on the thick end of 5w20, which is perfect, IMO.

Quaker State Ultimate Protection Full Syn runs quite a lot on the thickend for 5w20. If I was going to use QSUPFS for her CR-V then I'd use 0w20.

Quaker State prices at Walmart are excellent.

I bought her a NAPA Gold oil filter because I think it's the best.

 

[lilspenny]

Hello all. First, please forgive me because this is going to be a bit wordy. I’ve been a long-time lurker and thought I’d finally join as I have a question/concern I was hoping to have answered. I know this question has been asked before, so forgive the redundancy, but It’s me asking the question this time, wanting to hear from those who have knowledge on the subject for my own edification.



So let me begin with some minor background on myself. I’m a former Ford heavy-line tech. I worked for a Ford dealership from the mid ‘90’s to mid 2000’s. I’m not saying that to profess any kind of vast knowledge as it’s been ~30 years since I’ve worked on cars professionally and a lot has changed in those years. I love working on cars for fun but got to hate doing it for a living. Working at the dealer sucked the fun out of it and the life out of me, but it does provide some context for the question I’m going to ask. That said, I’ve done maintenance and repairs for all the cars in my family in the intervening years as it’s still a hobby I enjoy, as I’m sure is the case with a lot of you here on BITOG. It’s probably the love of cars, and likely all things mechanical that led many of us to this web forum to begin with.



I suppose I can say that I’m looking for confirmation, affirmation, validation, and perhaps absolution lol. Anyway, when I was training in Ford’s program back then, when the engineer came in to teach us on “engine theory” or whatever it was called, when speaking about lubrication, he said something that stuck with me. He basically said that the oil viscosity doesn’t matter as much as the oil spec. In other words, if the motor calls for, for example, an API SP oil (not sure what it was back then, SH or SJ maybe?) then any API SP oil (or whatever API spec the engine called for) will be fine for that motor regardless of viscosity as it will have the additive package necessary to properly lubricate and protect the engine, and that viscosity selection should be based primarily on driving and climate conditions.



I’ve followed this advice since then and it’s never failed me. But, engines were less complicated back then. Variable valve timing systems such as BMW VANOS and Honda’s VTEC had only been introduced a few years prior and were still relatively new. Ford’s modular 4.6L SOHC engine and it’s self-grenading 5.4L big brother were still relatively new for Ford. More importantly, oil grades/viscosities were still fairly simple. You had the usual suspects for most passenger vehicles which were, of course, your 5w-30’s, your 10w-30’s and 40’s, and of course the 15 and 20w oils as well. I think Mobil1 0w-30 had just been introduced around this time, and was near impossible to find, so it may as well not have existed. Of course, this is mid-90’s so internet was still in its infancy as well.



Anyway, now we come to the meat of the matter, my reason for posting. We recently purchased a RAV4 Prime for my wife, which calls for 0w-16, and I will likely be purchasing the new ’26 for myself when they come out, which will no doubt “mandate” 0w-8, despite having the same power train (or so I’ve heard). I have a hard time wrapping my head around these water thin oils. I’ve been educating myself here on this board, reading about cSt’s, HTHS, TBN etc., comparing the w-8, w-16, w-20 oils to the more traditional viscosities, and don’t like what I see. Maybe, maaaybe I can wrap my head around a w-20. For those who don’t know, all the hybrid Rav’s are built in Japan, and are both a U.S. and JDM car, so for giggles, I went to the Toyota Japan website and downloaded the owner’s manual for my wife's car. It’s in Japanese of course, but Google translate is your friend. Unlike the U.S. manual which states “must use” 0w-16 , the Japanese manual states that 0w-16 is recommended for best fuel economy, but that the engine is also “compatible” with 0w-20, 5w-20, and 5w-30 motor oils, the caveat being that they meet API SP or Ilsac GF6A specs. Kinda what the old engineer was teaching us in our class back 30 years ago.



I’ve been on various Toyota forums, but they aren’t much help. The conversations usually devolve into people stating that you must use what’s stated in the manual because the engineers designed the engine only to run on that oil, and that the oil pump is electronically controlled and programmed specifically for that oil and so on. If you read far enough through these threads, you start to see pretty quickly that most of these individuals, as well intentioned as they are, know little about cars. I’ve researched it to death, and the pump is actually a chain driven mechanical pump. The only “electronically controlled” aspect of the lubrication system is an oil pressure control valve, which from what I’ve read in various places is regulated by the ECM via info provided by oil pressure and temperature sensors in the engine. I think this myth was started by the Car Care Nut. I love his channel and am a subscriber, but even he contradicted himself in this statement in a later video when he’s tearing down one of these engines and he points out the chain driven pump.



Anyway, I guess that I’ve answered my own question, but wanted to ask those of you who know as I’ve been out of it for so long. Was the old engineer right? Will I be ok using any viscosity as long as I stick with the proper API/Ilsac spec? If that’s the case, I will probably go with a 0w-30 since I want to ensure our cars last. Her last car was 12 years old when we traded it in, and mine is about that age now. We typically keep our vehicles for at least 12-15 years and want to ensure these last at least as long.



Your input and knowledge are much appreciated.

I bought a new 2013 v6 Accord and ran nothing but 0w40 Mobil 1 and changed the oil every 5k miles. Traded the car when the mileage was100k for a new truck. At that time the Accord was not using any measurable amount of oil that I could tell. My wife now owns a 2019 RDX with 90k miles. I have been using Amsoil 0w20 in the winter and Ultra Platinum 5w30 in all other seasons, changing every 5k miles. No easily measured oil consumption there either. I have always looked for signs of oil usage, but haven't noticed any. Common sense goes a long way toward engine longevity. In my truck I have always used the indicated 5w30 except for heavy hauling trips in the summer. Then I've used 5w40. No way would I, if I had a new Rav 4, use 0w20 in summertime. No way would I use 0w8 at all, ever. I may be showing my age, 68, and some people might consider my practices similar to a loaded cannon rolling downhill in a crowd of people. But... so far things have worked out ok for me. Btw, I live in northern Alabama.

 

[Carlostrece]

I've changed my mind about using 5w20 in my neighbors Honda CR-V because her CR-V is a bit of an oil burner I have learned. So next time I'll put 5w30 in it.

 

[RMaybeth]

What i hear you saying is: "I want to use the best oil so my car lives the longest but there is too much information and I'm confused about what oil I should actually use."

I felt the exact same way when i first got my 2017 Lexus LS 460. It has 69,500 miles when I bought it in May 2023 but that didn't matter really, because I did what I always do when I get another new-to-me car: I assumed the previous owner was the world's biggest cheapskate as well as the laziest, and never maintained a thing on it. So the first thing, of many, to do to it was an oil change. But what oil?

While lurking in several car forums, including this one, I read about this supposed miracle oil in a bottle i.e. Pennzoil Ultra Platinum (not to be confused with "Pennzoil Platinum"). After reading comments and posts by people who raved about how great this stuff is, I decided to use Ultra Platinum for a while. Since the big V8 on this car takes almost two gallons of oil, it was not exactly a cheap decision either, especially since I had no intention of driving even halfway to Lexus' "recommended" 10,000 mile interval. (After working in automotive around 50 years, professionally and otherwise, and torn apart scores of engines, I firmly believe the brand of oil you put in is not nearly as important as how frequently you change it).

But now having picked the brand, it was the choice of viscosity that was in question. And for a while I just unquestioningly used Lexus' "recommended" 0w-20 weight oil - after all, they built the car, right? Why would they steer me wrong? But about a year into ownership, I read something that made me question that.

On a Lexus forum, another LS 460 owner, who lives and drives in Ireland, had noticed a significant difference in his (Irish) owner's manual, and the owner's manual for cars sold in the USA. He was wondering why his Irish owner's manual essentially said, it was ok to use any weight of engine oil appropriate for conditions. So for summer you can use 5w-30 or even 10w-50 weight oil if you wanted or needed to. Meanwhile the American manual stressed "use 0w-20 always, period, full stop! You can use as heavy as 5w-20 oil in a pinch, but if you do, you must - MUST change it right back to a zero weight oil at the next oil change." So the forum poster was curious - why would Lexus recommend 5w-30, 10w-30, or even 10w-50, in one country - and in fact Lexus recommends this in every country EXCEPT the USA - but not for American owned cars?
Then an oil expert on the same forum explained, the automakers were so hamstrung by American regulations and requirements, the 0w-20 oil was recommended solely to help the car to meet the government MPG requirements. Yep, Lexus was forced to require zero weight oils in their engines, as if the (miniscule, at best) difference in MPG between a 0w-20 oil and 5w-30 will somehow increase the car's MPG just a little!

And that was when I switched to 5w-30 in this car. (And the idle is noticeably smoother too, whatever that's worth). My whole point being, the days of simply trusting the manufacturer's recommendations on maintenance items, are over. Especially when it comes to maintenance intervals - for most items, the "recommended service intervals" are much too long. Any carmaker, or anybody else for that matter, who actually claims "your auto transmission fluid never needs to be changed" is somebody who says things that should not be taken at face value.

 

[kschachn]

What i hear you saying is: "I want to use the best oil so my car lives the longest but there is too much information and I'm confused about what oil I should actually use."
I felt the exact same way when i first got my 2017 Lexus LS 460. It has 69,500 miles when I bought it in May 2023 but that didn't matter really, because I did what I always do when I get another new-to-me car: I assumed the previous owner was the world's biggest cheapskate as well as the laziest, and never maintained a thing on it. So the first thing, of many, to do to it was an oil change. But what oil?
While lurking in several car forums, including this one, I read about this supposed miracle oil in a bottle i.e. Pennzoil Ultra Platinum (not to be confused with "Pennzoil Platinum"). After reading comments and posts by people who raved about how great this stuff is, I decided to use Ultra Platinum for a while. Since the big V8 on this car takes almost two gallons of oil, it was not exactly a cheap decision either, especially since I had no intention of driving even halfway to Lexus' "recommended" 10,000 mile interval. (After working in automotive around 50 years, professionally and otherwise, and torn apart scores of engines, I firmly believe the brand of oil you put in is not nearly as important as how frequently you change it).

But now having picked the brand, it was the choice of viscosity that was still in question. For a while I just unquestioningly followed Lexus' "recommended" 0w-20 weight - after all, they built the car, right? Why would they steer me wrong? But about a year into ownership, I read something that made me question that.

On a Lexus forum, another LS 460 owner, who lives and drives in Ireland, had noticed a significant difference in his (Irish) owner's manual, and the owner's manual for cars sold in the USA. He was wondering why his Irish owner's manual said it was ok to use any weight oil appropriate for conditions. So for summer you could use 5w-30 and even 10w-50 weight oil if you wanted or needed to. Meanwhile the American manual stressed "use 0w-20 always, period, full stop! You can use as heavy as 5w-20 oil in a pinch, but if you do, you must - MUST change it right back to a zero weight oil at the next oil change." So the forum poster was curious - why would Lexus recommend 5w-30, 10w-30, or even 10w-50, in one country (and in fact Lexus recommends this in every country EXCEPT the USA) but not for the USA?
Then an oil expert on the same forum explained, the zero weight oils were only used to meet government MPG requirements. And the automakers were so hamstrung by the regulations, the 0w-20 oil was factory fill, only to help the car to meet the government MPG requirements. Yep, Lexus was forced to require zero weight oils in their engines, as if the (miniscule, at best) difference between a 0w-20 oil and 5w-30 would somehow increase the car's MPG just a little!

So after that I started using 5w-30 in this car. And the idle is (probably) noticeably smoother too. Point being, we have reached a point in time where you can no longer simply trust the manufacturer's recommendations anymore, for anything to do with your car's maintenance.

Those aren't "zero weight" oils. You're not understanding how grades work.