Confessions of a Recovering Thickie

[ZeeOSix]

It said lower friction and less wear.

Rings are also in mixed and boundary lubrication realms, so the coating would come into play in those realms, not really the oil viscosity so much. That's probably what they are talking about. I don't see how any coating is going to be "sensitive to viscosity". One trick these engines use that spec 0W-8 and 0W-16 is to use slick coatings to take the wear when the MOFT goes to zero. Sounds like is what these coated rings are also doing.

 

[siriusc1024]

Rings are also in mixed and boundary lubrication realms, so the coating would come into play in those realms, not really the oil viscosity so much. That's probably what they are talking about. I don't see how any coating is going to be "sensitive to viscosity". On trick these engines use that spec 0W-8 and 0W-16 is to use coatings to take the wear when the MOFT goes to zero. Sounds like is what these coated rings are also doing.

Buddy, the paper just said what it does. I'm not the one saying it. It's a combination of both coating and oil viscosity. They highlighted 'synergistic' to drive the point home.

 

[ZeeOSix]

I do understand MOFT. So do the people designing the engines. If MOFT is sufficient then it's sufficient. There are tradeoffs. That's design optimization.

Like said earlier, you don't know if the MOFT is always sufficient in all conditions ... until it's not. If the MOFT is on the ragged edge at times, it will cause some added wear, but nobody will know unless they tore down the engine to inspect parts. Engines will run a long time and seem to run fine even with a good amount of wear. So what's wrong with some added film thickness for more wear protection between moving parts.

The "tradeoffs" and "design optimization" has the CAFE factor baked-in, so they specify the lowest viscosity possible, but that doesn't necessarily mean that the engine has optimum wear protection from the specified viscosity, when a grade higher would do better (ie, Ford going from 5W-20 to 5W-30, and not because they just don't like CAFE). Same engines used in other countries without EPA/CAFE involvement show a whole range of recommended oil viscosity. OMs have been posted here many times showing that.

How long does stuff last on the track in general?

Depends how much the MOFT goes to zero because the viscostiy was insufficient.

 

[siriusc1024]

Like said earlier, you don't know if the MOFT is always sufficient in all conditions ... until it's not. If the MOFT is on the ragged edge at times, it will cause some added wear, but nobody will know unless they tore down the engine to inspect parts. Engines will run a long time and seem to run fine even with a good amount of wear. So what's wrong with some added film thickness for more wear protection between moving parts.


Depends how much the MOFT goes to zero because the viscostiy was insufficient.

Right, so then a judgment call is in order. You're operating the vehicle outside of expected conditions, so you need to adjust. If not then no need to adjust, and I'll say that doing so potentially reduces designed life.

But idk if you saw, I edited an earlier comment showing how TPR makes ta-C rings and is a supplier to Toyota. So this combined with that paper gives some insight into how Toyota gets away with seemingly ridiculous low viscosity oils. I feel like I learned something, hopefully you're enriched. Isn't that progress?

 

[ZeeOSix]

Right, so then a judgment call is in order. You're operating the vehicle outside of expected conditions, so you need to adjust. If not then no need to adjust, and I'll say that doing so potentially reduces designed life.

I'm not going to stop and change the oil on the side of the road to a higher grade every time before I want to row through the gears to redline may times a day, lol. Hence, I run a 5W-30 instead of 5W-20 so I can drive it like I stole it when I feel like it with some added MOFT headroom between parts.

Doing what potentially reduces designed life?

But idk if you saw, I edited an earlier comment showing how TPR makes ta-C rings and is a supplier to Toyota. So this combined with that paper gives some insight into how Toyota gets away with seemingly ridiculous low viscosity oils. I feel like I learned something, hopefully you're enriched. Isn't that progress?

Could be Toyota is using such coatings in their engines specifying 0W-8 or 0W-16. This is one reason they can run such thin oil.

To add ... after reading more on that study link, it sounds like these coatings are also used to help prevent wear during cold starts and oil warm-up when there's a potential of some lack of lubrication. Might be a good application for hybrids with lots of stop/start episodes. The coatings give less friction when there's not enough oil and therefore help reduce wear compared to no coating.

 

[siriusc1024]

What are you driving?

Going against spec potentially reduces design life.

 

[ZeeOSix]

What are you driving?

Mustang GT which specified 5W-20. I went to 5W-30 on the first oil change. The Z06 LS6 specified 5W-30 and that's what I used. Like said before, anything that's specifying xW-20 or less can benefit from going up a grade. Anything specifying a xW-30 can benefit from going up a grade or even two if used on the race track, but would suffice well for street use (except in "Mexico").

Going against spec potentially reduces design life.

I highly doubt it if the right W grade is used. What do you think is going to have reduced life with a grade or two higher KV100? Even LSJr and Engineering Explained in one of their videos even mention going up in viscosity is no concern, but going down a grade is. Someone here put Redline "0W5" racing oil in a twin turboed V6 as an "experiment" {look for the thread), and didn't run it long and the UOA already showed increase wear metals and the oil filter had some metallic particles. Go figure.

 

[siriusc1024]

Just wondering why you don't put in Xw-40 or -50?

 

[tolian21]

What are you driving?

Going against spec potentially reduces design life.

I am using Mexican owner manual for my Honda engine that has 5w-30 in it

 

[ltslimjim]

Just wondering why you don't put in Xw-40 or -50?

What’s funny is, depending on the vehicle that may be among several different grades that are “appropriate“

US CAFE exists and recommend thinner grades as a result. Go to another country, and suddenly the approach is no longer “as thin as possible” with no room to spare. and on the line of too thin. Is it any wonder you can go up several grades? therefore, going up a single grade isn’t really that big of a deal.

 

[kschachn]

See don't do that. Just because it doesn't fit with what you think doesn't mean reject it. That's what I was saying about being self-limiting and not growing.

Ever notice how an oil standard is set then there is all this talk about what the standards mean? People here aren't setting the specs. They are learning about them. There's always going to be a lag of knowledge. So when you take information and reject it you're missing out on a growth opportunity.

So I learned something, and you chose not to. What's the saying about the difference between ignorance and stupidity? Knowing and choosing not to know? You're better than that.

You can't even tell me which engines use that coating. Further, I highly doubt anyone here knew about that. I'll admit I looked it up. The reason I looked it up is because I'm not closed to the notion that 0w-20 where specified is required beyond simple parasitic losses and EPA targets. You don't have to be, either. Nobody is keeping score of who's right, and if they are then whatever.

What on earth are you trying to convey that is of a technical nature?

No oil of a higher HT/HS will cause damage. It will slightly increase fuel consumption but you're not going to cause damage.

Ignorance and stupidity is not involved, physics is. I have no idea what "growth opportunity" you're trying to promulgate here.

 

[kschachn]

Right, so then a judgment call is in order. You're operating the vehicle outside of expected conditions, so you need to adjust. If not then no need to adjust, and I'll say that doing so potentially reduces designed life.

But idk if you saw, I edited an earlier comment showing how TPR makes ta-C rings and is a supplier to Toyota. So this combined with that paper gives some insight into how Toyota gets away with seemingly ridiculous low viscosity oils. I feel like I learned something, hopefully you're enriched. Isn't that progress?

Yes you can reduce designed life by using an oil with an insufficient HT/HS.

 

[kschachn]

What are you driving?

Going against spec potentially reduces design life.

Oil grades are not a spec, they are a recommendation. Plus the fact that in recent times they aren't based on anything but what the manufacturer is required to do based on EPA testing. In other words, politics. What is recommended in the manual is the lowest HT/HS that can be used to prevent excessive wear and nothing else. It is not necessarily optimal for longevity. It is acceptable under most circumstances to prevent excessive wear. That's it.

 

[tolian21]

US CAFE exists and recommend thinner grades as a result. Go to another country, and suddenly the approach is no longer “as thin as possible” with no room to spare. and on the line of too thin

Somehow foreign owner manuals are totally ignored by people that argue about thin oils being “better”

 

[ltslimjim]

Somehow foreign owner manuals are totally ignored by people that argue about thin oils being “better”

At a minimum, it completely obliterates the idea you must use a certain oil grade unless you believe physics changes based on which country you live in. Maybe Antarctica? The North Pole? Sure, use the best winter grade possible lol

 

[tolian21]

At a minimum, it completely obliterate the idea you must use a certain oil unless you believe physics changes based on which country you live in. Maybe Antarctica? The North Pole? Sure, use the best winter grade possible lol

Some say tolerances are different in mexico, different oil additives, different gasoline…. Its total BS.

 

[Jetronic]

Just wondering why you don't put in Xw-40 or -50?

don't have any on hand, but have run Redline 20W-50 in my 5W-30 specced car (acea C2).

 

[tolian21]

don't have any on hand, but have run Redline 20W-50 in my 5W-30 specced car (acea C2).

The next thing they will ask why not put 75w-90 transfer oil

 

[Hohn]

It said better performance at the tested temps. It didn't say temp-dependent.

It said lower friction and less wear.

All that was in bold...

Rings:
https://www.nti-nanofilm.com/ultra-...us-carbon-tac-for-diesel-engine-piston-rings/

More rings:
"3-part composition of TOP, 2ND and OIL rings, the OIL ring is a 3-piece type"
https://www.tpr.co.jp/tp_e/products/powertrain/pistonring/

Btw, TPR is a supplier to Toyota.

They tested other coatings, as well.

Take a peek at the accompanying graphs from the paper you cite:

The steady-state advantage of the 0w20 at 25°C is on the order of 0.01 in friction coefficient.

At 100C, the steady state advantage is markedly less, perhaps 0.005.

Now consider the cyclic start-stop curves. The first start advantage of the 0w40 is about 0.01. In subsequent starts, their data suggests an advantage for the thinner oil of up to a whopping 0.0025.


This is the context for my commentary as follows:

• To the extent it's real (again, not actual engine testing), the advantage of the thinner oil is:
  • tiny at best
  • not present at initial start when it matters most
  • present *only* when combined with this DLC-like coating
  • Noteworthy ONLY because of the known fact of the converse. In other words, this is the exception that proves the rule. And what rule is that? The thicker oil provides better wear protection in most cases. If it wasn't for that "rule" nobody would care about this novel coating test data as an exception to it.

 

[siriusc1024]

Oil grades are not a spec, they are a recommendation. Plus the fact that in recent times they aren't based on anything but what the manufacturer is required to do based on EPA testing. In other words, politics. What is recommended in the manual is the lowest HT/HS that can be used to prevent excessive wear and nothing else. It is not necessarily optimal for longevity. It is acceptable under most circumstances to prevent excessive wear. That's it.

C20, C30, A40...those euro specs you love. They have explicitly defined viscosity ranges.