NONE of what I’ve posted is in reliance upon YT videos, zero. It would really be interesting to see what metrics support a blanket assertion that higher HT/HS “always” yields less wear.
We finally got some... 0W-8.
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Why do you think the same makers are still recommending xw-8/16/20s for models like the Camry, Accord, Civic, etc.??? For those vehicles which will not see any practical added value, then why not the lower vis oils? The point is not to play “tastes great/less filling” games, as if “thicker” oils possess some inherent superior value. If the application requires a higher vis oil, then of course, they should recommend that, and wise owners will use that.
You've been here a long time, so maybe you've seen some of the studies done were different oil viscosity was used to test and measure wear in a running engine, and the conclusion is with the same AW/AF package that the higher viscosity results in less wear. It's a fact that will never change because viscosity is the main factor that determines what the MOFT will be between moving parts. The film thickness (MOFT) is the main contributor to preventing wear between moving parts. The film strength (ie, the AW/AF additives) is that helps mitigate wear after the MOFT goes to zero. It's been discussed over and over in this forum.
Again, xW-8 and xW-16 are only used in vehicles specifically designed with specially engineered features to use that oil. Would you put 0W-8 in an engine speced for xW-20 or xW-30? You could, but it's not going to protect that engine from increased wear. Fact is, engines don't care if the oil is thicker, they only care if the oil is not thick enough for adequate lubrication and wear protection. Nobody cares what viscosity other people use ... but this is a technical discussion and there's plenty of proof that thicker oil gives more film thickness which results in less wear. Nothing will ever change the physics of viscosity between two moving parts and the resulting oil film thickness.
Thicker oil does possess an inherent superior valve ... the creation of a better film thickness between moving parts to give added protection from wear. It's a simple principle of Tribology that will never change.
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I do fully understand the difference between “winter” and hot ratings. Of course, they’re different, and of course, for proper protection across the range have to be adequate.
Yes, more film thickness, all things being equal, should provide more ultimate ability to keep metal surfaces separated. But if the engine involved does not present conditions in which the added protection will ever make a significant difference, then how does it really matter? If there’s fully sufficient MOFT across the operating range using a lower vis oil, then why use a thicker one?
This is hard to believe. I joined this site TWENTY years ago, and we’re still chasing our tails, freaking out, completely losing sight of when the differences between viscosities matter, and when they may not. In the case of the aforementioned Coyote, Ford looked at the results, and wisely admitted that there WAS a practical reason to shift back to the 5w-30 oil. Against that specific good example of when there is a difference, we now have ~25 years of experience with legions of vehicles which have lived long, unremarkable lives using “thinner” oils their whole lives. There’s a “metric” that nobody can ignore.
How do you know there's always a sufficient MOFT going on in all the operating conditions? There's no "MOFT real time monitoring system" going on for every moving and rubbing component inside an engine while you're driving down the road that all of a sudden goes off and warns that the MOFT in the journal bearings or at the rings is critically low. The easiest thing to do in order to give some protection headroom is go up a grade. Maybe go up two for track use in some instances. It's a no-brainer if someone is concerned about better wear protection. If not, then just run what the OM says. If you're happy to run as thin as possible, then do it.
I've studied the life of the Coyote a lot, and there was talk on one chat board where the Ford engineers wanted to spec 5W-30 for the Coyote from the beginning based on development testing. But apparently the hand of CAFE swooped in back then and Ford folded. It took Ford this long to realize using 5W-30 makes enough difference to forget about the CAFE credits impact. To me, that says a lot. Based on lots of wear studies, every engine is going to have some better wear protection with a grade above any engine specifying xW-8 through xW-20. As always, use the correct W grade for your anticipated cold start-up conditions.
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As for how we know that MOFT is sufficient, I think it’s a safe inference from what I said before: a quarter century long record of no drama with regular drivers using recommended oils. Of course, not everyone does, some maltreat their cars and so on, but again, really, with 25 years of this, by now, you’d have every Ralph Nader type in the universe SWARMING the car makers with class action lawsuits if it could be shown that use of lower vis oils, on the maker’s recommendation, was causing premature engine death. Beyond that, I actually agree with you. Long before I joined BITOG in 2004, I remember the rule of thumb that it was ok to go one up or down from the recommended grade.
IMO, the Coyote example proves, or maybe strongly supports, what we’re both saying. To their great credit, Ford realized that in that especially demanding application, that it would be wiser to shift up a grade and spec 5w-30. Seriously, I’d really love to have access to the database of info that led them to this decision. Equally compelling, of course, is that they DID NOT make a similar change to other engines in their product line, for which, presumably, there is an equally well established body of evidence establishing that the lower vis oils work well.
Also, apologies to you and the others. If there was confusion about my grasp of what the ratings of a particular oil mean (e.g. 0w-20, etc.), then the fault is mine for NOT expressing the points I’ve been trying to make clearly.
It's not about engines failing from the use of thinner oil. It's about having more wear protection from higher viscosity and reducing wear over the long run. Nobody is claiming the specified oil will smoke an engine with normal use on the streets. It could however lead to engine damage or at least more wear if the speced oil was used in the wrong conditions, like on the track for instance or really taxing the engine on the streets. Guy on YT who tracked his car thought he'd just run the speced 5W-20 on the track because the "oil temp would stay lower". He inspected the rod bearings after a couple track sessions, and they all showed a lot of abnormal wear. Not enough MOFT for the use conditions in that case.
And it's possible that even some engines used for normal street driving would have less wear and stay more mechanically healthy throughot its life if a thicker oil (one grade up) was used in those engines specifying xW-8 thru xW-20. Going up a grade is an easy way to add some wear protection. Only thing you may lose is a sliver of fuel economy. Many here would rather have the added wear protection.
You like to move goal posts.
You like to read carelessly and make undue assumptions.
But, respectfully, many do, and that’s one of the main ideas I’m responding to. One of the things that led me to this site in the first place was running some searches after I had read some postings by a guy who was loudly and bitterly complaining about how dangerous 5w-20 oil was to engines, and he was predicting that we’d soon be seeing waves of failed engines. What stands out in my memory of his posted claims was him dismissing 5w-20 as little more than cutting oil. He added something to the effect that it would be insufficient for use with a sharpening stone. That was the essence of it. I imagine his head would explode at the thought of people putting 0w-EIGHT oil into passenger car engines.
And just a few weeks ago, I personally experienced yet another example of the “calamity” position at my usual AutoZone when I asked the clerk on duty when they’d start stocking 0w-8. It’s not too much of a stretch to say he saw me as a blaspheming heretic for even speaking the words, let alone considering using the stuff… It may be very hard to believe, but I did politely decline to engage!
This is why it is essential and critical to stick to physics and keep the discussion on a technical level. When people start throwing around terms such as blasphemy and heretics it starts to wander, and threads get dragged out for needless reasons.But, respectfully, many do, and that’s one of the main ideas I’m responding to. One of the things that led me to this site in the first place was running some searches after I had read some postings by a guy who was loudly and bitterly complaining about how dangerous 5w-20 oil was to engines, and he was predicting that we’d soon be seeing waves of failed engines. What stands out in my memory of his posted claims was him dismissing 5w-20 as little more than cutting oil. He added something to the effect that it would be insufficient for use with a sharpening stone. That was the essence of it. I imagine his head would explode at the thought of people putting 0w-EIGHT oil into passenger car engines.
And just a few weeks ago, I personally experienced yet another example of the “calamity” position at my usual AutoZone when I asked the clerk on duty when they’d start stocking 0w-8. It’s not too much of a stretch to say he saw me as a blaspheming heretic for even speaking the words, let alone considering using the stuff… It may be very hard to believe, but I did politely decline to engage!
An admirable goal, but at the end of the day, this is an informal discussion forum. It’s waaay better than a lot of them, but, IMO, there’s simply no consistent way to achieve the level of technical purity you’re suggesting. To get that, you’ve got to find and digest the peer reviewed scientific or academic material. Of course, you’re 110% entitled to disagree (it’s a discussion forum, of course!), but my use of the colorful terms is intended to highlight precisely what you’re getting after: ignoring the scientific and technical information available and basing a position upon one’s prejudices and opinions.
The young man at AutoZone was clearly well intended. He hoped and meant to offer good advice to a customer, but in reality, his notably emotional reaction was premised upon something other than the scientific and technical. That was the basis of my use of those colorful terms, not a lack of discipline or a desire lead the conversation away from the technical or scientific.
I don't think many here believe a specified oil from the manufacturer is going to cause any engine to fail when the vehicle is used as intended (ie, no track use, etc). Many here do however believe (based on many technical studies) that thicker oil will provide more film thickness and therefore better wear protection over the long run. That's a basic fact of Tribology that will never change. Then you have the people who say the car will rust out or get totaled before it matters anyway, which could be true, but the purists still want to focus on doing things that would result in less wear regardless of what might happen to the vehicle in the future.
Don't listen to people about oil if they don't pass the test of knowing the difference between the W grade and the KV100 grade of a multi-grade oil.
And if they don't have a basic understanding of Tribology, then they have zero technical background on the subject matter. Most people don't even know the basics of how a journal bearing works or the importance of the MOFT inside of it while running, or what a PD oil pump is or how an engine oiling system works. How do you think they are going to understand how oil viscosity effects the dynamics and resulting wear of moving parts inside an engine?There have been lots of official wear studies posted and discussed over the years on this chat board. There is a distinct connection between viscosity and the film thickness it creates between moving parts (the basic physics of Tribology), and the effect on resulting wear - less film thickness means more rubbing and more wear with all other factors held constant. The science and testing results always point to the same conclusion: Oil viscosity is the main factor that keeps moving parts separated to mitigate rubbing and wear. The AF/AW additives become more heavily relied on after the film thickness is inadequate and moving parts are heavily contacting each other. Stressing an engine makes the rubbing forces higher, and therefore more viscosity adds protection in those cases. Thinner and thinner oils rely more on the AF/AW tribofilm to mitigate wear vs relying on the viscosity. And a whole other side subject aspect of engine wear is the wear relationship with respect to oil cleaniness (oil filtration), and there have been lots of discussions around that subject matter in the oil filter forum. There are also plenty of wear studies about the relatiionship between oil cleaniness and wear that always concludes that cleaner oil means less wear. So, knowing the results of many engine wear studies over the years, it's not hard to conclude what helps mitiates engine wear vs not.
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It's so thin, oil from the air actually leaks into the bottle.
If I had to bet money, I’d go with most people NOT passing this test. I wouldn’t have when those early internet searches, and my suspicion of The Motor Oil Bible, brought me to this site in 2004. I’ve learned many lessons over the last 20 years, both here, and from the numerous sources BITOG has led me to. We’ve been through the facts as you lay them out here many times during the years I’ve been here. I don’t see anything that appears incorrect in your post, which leads to a point I’ve made before: it’s really a matter of emphasis. This is why I have resorted to the perhaps sloppy (at least scientifically sloppy) “tastes great, less filling” metaphor. As with those long ago arguing beer drinkers, the real “argument” is about what we are emphasizing. Sure, a 0w-20 may theoretically protect better than an oil of lower vis, but in the real world, will it make a meaningful difference? Stripped to its barest essence, if Oil A, which according to tribological science, protects an engine “better” than Oil B, but does so in a way and to a degree such that it has no practical impact upon the service life of the vehicle, does it really matter in the end whether an owner chooses A or B? For some, it will, and that’s fine. I’m unconcerned about using the recommended 0w-8 in my car, but do plan to try the 0w-16 at some point soon, just to see if I can discern any observable differences in the car’s behavior. I will remain open minded about the possibilities.Don't listen to people about oil if they don't pass the test of knowing the difference between the W grade and the KV100 grade of a multi-grade oil.
Hey, next up after 0w-2 (no zero) are deemed too thick, AIR BEARINGS! Of course, air is a compressible fluid, so it might take a couple years before it can be adapted for use in high performance engines! Relax guys, that’s oil humor — life is too short to be too serious…
Patman
Staff member
This is where I am at with my 2016 Civic. A lot of people might say that I should switch to 5w30 or 0w30 instead of 0w20. But I’m confident that with the gentle driving that I do with this car, combined with it being driven long distances on the highway every day, should get me well beyond 500,000 km with ease. Even 600 to 700,000 is likely. So I really would not benefit from going up a grade with this car, in fact I really enjoy the MPG it gets me (close to 50 MPG average in the warmer months) Maybe I’m only getting 0.5 MPG better with the 0w20 but over many years of driving (at 20,000 miles+ per year) that will be a decent amount of savings for me. I will be the first one to admit I was wrong if this engine wears out on me but I’m actually very confident that it won’t.
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Is there anything about oil pressure creates a distance in the bearings in all this writing? Piston rings, that’s a lot different. I use what the cap says, it’s a lot less to read.
If the oiling system can't provide an adequate volume of oil to the required parts, then it's an oiling system design issue (like not getting adequate volume to all bearings), not a viscosity used issue unless the wrong W grade is used in very cold weather conditions. Cold start pumpability (the W grade) is way more important when doing very cold start-ups than the KV100 used when and engine is at operating temperature. That why the same engine can tolerate xW-20 to xW-50 or 60. But use the wrong W grade and starve the engine of oil volume and you'll be asking for problems.
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