0W-30 Oil
 

So, at about 40k miles and for the subsequent 35k miles, my 2016 developed this death rattle right at 3400RPM. Many members here said it was most likely the VVT-i cam mechanism. At first it only happened occasionally (once a tankful) but then gradually became regular and predictable. It usually happened when outside temps were warm, above 75° or so. After perusing some schematics, I thought perhaps loose tolerances so for my last oil change I put in 0W-30, Mobil 1. It's been about 1800 miles since then, temps have been 90-115 degrees and I no longer have the death rattle, at all. Surprisingly (coincidence?), the crickets have disappeared too.
Just thought I'd let you know...

I've been running that oil for about 40k with no problems, I've been pleased.
https://i.imgur.com/JI3IaW8.jpg
I recently switched to 0w40 to give that a try, so far things seem good. I will post those results as well.

Thanks for the info .. :thumbsup:

Back-in-the-day, if a car started burning oil, we would simply put in heavier oil - till we saved up for a set of piston rings...:D


humfrz

And 3 angle valve job. If you did rings without valves, or vice versa, you just immediately blew out the other. Both were required.

I made the same mistake with "make-up" oil. Never heard of the term.

Well, yes, as long as you had the head off, might as well have the valves ground/replaced ... :)

Yes, mill the head, more carburetors, higher lift cam, headers, GMC truck clutch, traction masters .. :thumbup:


humfrz

Also, I just checked my.oil level today. Consumption is practically zero. With the 0W-20, my FRS was using/losing/burning one quart every 3k miles.
Makes me wonder if the engine was actually designed to use something thicker, like 5W-30 (which was so popular with carmakers 10years ago) but was ultimately specced with 0W-20 for fuel savings?

The engine wasn’t designed around 0W-20 since thicker viscosities are allowed by Subaru Japan.

Link?

<-- professional tribologist (friction, wear, and lubrication scientist) with some experience in PCMO additives. If you have a good source, I will gladly vet it and weigh in. I usually stay out of oil stuff as it's tons of hogwash mostly, but viscosity is the first line of defense for a motor and I take it quite seriously.

The 0W20 thing is purely a fuel economy play that is made possible by modern manufacturing practice. 0W30 (if available) would be quite sensible in warmer climates or for track days if within manufacturer's bounds.

I love these two points. :laughabove:


And absolutely agree. One of the reasons why I go for any name brand oil manufacturer that provides the smallest viscosity ranges between the 40 and 100 degrees.

Actually, it works the other way.

The low and high temp viscosities describe a property called Viscosity Index, or VI. VI is the tendency of the material to maintain viscosity over temperature. The basis for VI is 100, and that is for a "normal" oil that loses a "normal" amount of viscosity with a given rise in temperature. A material with a very high VI will not lose as much viscosity over a given temperature interval. Therefore a 15W30 oil behaves like a 15W oil at lower temps and a 30W oil at higher temps. It gains and loses the corresponding amounts of viscosity. A 5W40 oil behaves like a 5W at low temps (less increase in viscosity) and a 40W oil at high temps (less decrease in viscosity). The 5W40 oil experiences less shift in viscosity as the temperature changes in either direction, which is the characteristic behaviour of a high VI oil.

This is why I am not so worried about running a 0W30 oil - it will maintain viscosity at higher temps. A 5W30 oil could get a bit sticky at low temps.

I was under the impression that the higher 40C viscosity causes rougher starts, engine wear, and poorer MPG. As long as the 100C viscosity is comparable to the standards of the suggested weight, then the oil will be good at norm temp. This was my logic behind choosing the tighter range oils within the 0w20 weights. Also, since this reflects the viscosity index, should it go beyond 100 C, it will able to hold the ideal viscosity better than those other 0w20 oils that have a higher 40C viscosity but same 100C viscosity.


My concern was the 0W30 tends to have much higher 40C viscosity (I think they were around 60 cSt, whereas 0W20 have been 45 cSt (and as low as 35). At the 100C 0W30 vs 0W20 are pretty negligible .. like 10 cSt vs 8 cSt. Plus I'd like to stick with the manual's suggestion of 0w20 because my driving is pretty standard public road use.

Remember that you want to maintain a fixed viscosity at all temps. There is a significant drop from 40 to 100 for 15W30. As in, a lot of viscosity loss. Preventing that loss is important. So I look for very high VIs that lose less viscosity over that span and beyond.

I mean, you're welcome to your idea of how it works. Physics doesn't care. :)

It sounds like we're saying the same thing? Less viscosity deviation from what the manufacturers deem to be normal/ideal operating temperatures is what we want.


Since manufacturers suggested 0W20, then I assume they would want a lower viscosity at 40C (as this is much cooler temp than normal operating temperatures thus much more viscous than desirable) and normal standard 100C viscosity of ~8 cSt.


Last I checked our stock car when fully warmed up has oil temps around 100C as well. Thus I looked into the majority 0W20 oils' 100C viscosities and found them all to be ~8 cSt.


The majority of 0w20 at 40C were 44 cSt, but there were two 0w20 oils that were 35/36 cSt. Thus I have decided to use those two oils instead of the other 45 cSt oils.

Which two oils are those with the lower cSt numbers?

I gotta write a book but I need a real keyboard.

It's the confusing terminology. Basically, teh 0, 5, 20, etc are actual viscosity specs, but they are kind of inside out. It may be monday before I get to my laptop, but I will be back to elaborate.

Without an actual viscometer in hand, and without controlling for the nature of degradation that occurs, the "clean" or unused viscosity is a guide. The difference between 35 and 40 cSt may not be that much after a few hours of running.

1) Toyota Genuine Motor Oil 0W20

2) Idemitsu Zepro Eco Medalist Advanced Moly 0W20 & Idemitsu Zepro Eco Medalist 0W20 [I essentially considered these two oils the same, one has a bit more moly emphasis and probably a bit of other differences]

----

Edit - Forgot about the third option, I don't think about it because its so expensive.

3) Eneos Sustina 0W20

I simply compared all the clean oil viscosity values of 0W20 oils. I don't have any interests in oils outside of 0W20 so I can stay per manual's specs, especially since my driving is at most a spirited canyon drive.


Yes clean/unused/virgin oil viscosity is merely a guide, but absolutely a great place to start (especially since that's all I have to work with and I'm too lazy to collect and compare used oils while standardizing for room conditions; full synthetic oils are also less prone to degradation). And yes, the temperatures aren't going to remain at 40C. But the rough starts are my primary concern because 1) all the 100C viscosity values of 0W20 oils are all about 8 cSt (thus similar viscosity at normal operating temps), 2) majority of engine wear is during the cold starts (or so I have read in various places), and 3) I'm making a general assumption that any good brand oil will provide sufficient engine protection at ideal operating/warmed up temperatures.


I also feel the difference for a 40C 35 cSt vs 45 cSt is quite significant - 28.6% greater (45/35). You should also consider that 40C is still very hot (104F).
Let say its 50F outside (10C), which isn't that cold. Chart the following viscosities: Idemitsu Zepro 0W20 40C - 34.9 cSt, 100c - 7.9 cSt vs Mobil1 0W20 40C - 44.8 cSt, 100c - 8.7 cSt.
Use this (or any other graphing calculator of your choice): https://www.widman.biz/English/Calculators/Graph.html
At 50F/10C, you're looking at a rough start of 120 cSt vs 180 cSt. That is 50% more viscosity at real morning temps (180/120). Of course, this is gap is even more severe if you live somewhere even colder. Say its 0C (32F) outside, you're looking at 200 cSt vs 320 cSt (60% - 320/200).
Now I know these graphs are theoretical calculations, but accurate enough to provide realistic expectations .. probably <5% deviation.



For someone like me, who does lots of short distance driving, I also want to provide the least strain on my engine when its cold. And my (edit: by*) least strain, I consider it to be the oil that provides the viscosity closest to full operating temperatures of ~8 cSt (based on manufacturer's suggested 0W20 and the average 0W20 oil viscosity at 100C of ~8 cSt).

Sorry to ask for specifics now but, did your research give you data for Castrol Edge Extended? I've found my car to be happiest with this oil in the suggested 0W-20 weight, best mpg, easiest and quietest cold start and smoothest running on long road trips (which I do a lot of). This stuff https://www.castrol.com/en_us/united...motor-oil.html

I looked at the Castrol Edge, not the Castrol Edge Extended. But I did look it up for you (all information is provided from manufacturers): 40C - 45.1 cSt & 100C - 8.7 cSt.


I've pretty much looked up every major brand oil manufacturer and 40C have averaged 45±1 cSt.

I hope so! That's what the first number in the spec means. :D

Anyway... So if an oil is 45cSt at 40°C, it will change to some degree or another when the temp is ramped up or down. Again, that is a basic physical property of materials called VI.

The engine has two operating temps to be concerned with - ambient and running, so anywhere from -40°C to +45°C (for the Death Valley types), and then up around 105°C. The SAE viscosties are measured to account for the extremes - -40°C (or so, depending on grade) and 100°C. Of course, they are measured differently, just for fun. FWIW, the W stands for "Winter", presumably the coldest condition the oil will see. However, for practical purposes, it means cold start.

The info from @Bonburner is solid because it informs us about the higher number, and that is the one that we typically care about, so long as the car starts - ie - we have gotten past the cold operating condition. Once we get up into the operating range, then we have to be concerned about how the oil varies in viscosity with higher temps. This is where things get mushy for us, because we are running outside of the 100°C window.

Each spec (winter and summer) has a min 100°C viscosity and the "summer" ones have max viscosities, too. This is important. That max viscosity imposes a limit on the viscosity index. However, the range is broad enough that it touches the next grade up.

more to come....

The Miata manual confesses, if you look closely, that the purpose of the lighter oil recommendation is for corporate fuel economy CAFE.

It's OK if you burn your motor out prematurely, as long as the company can meet government fuel standards.

Sadly, I generally agree with this. That is why I am so interested to see a valid link to a ROW standard for heavier oil. If it exists, I will be all over it!

I find this interesting @MrDinkleman because a few years ago, at 40k miles, I specifically remember hearing a vvt rattle, or some kind vibration and knocking sound when hovering at 3400 rpm in 3rd gear. It happened on only two occasions after leaving the highway from long trips and during normal cruising, and after that never happened again! Perhaps something wearing in like timing chain tensioners? Or perhaps AVCS doing some sort of "programmed systems testing" nearing the end of the drivetrain warranty? :thinking emoji"

Interesting thoughts. When is valve adjustment called for?

My 4runner was one of the first 5th gens off the line and the oil spec from the manual was 5w30. About 6 month later Toyota sent a letter out saying that the spec should be 0w20, for US trucks only, because that is what they used for EPA testing. The Canada/Mexico spec is still 5w30, and the letter states that you can still use it "only when 0w20 is not available" ;) ;)

The change interval is 10,000 miles and an analysis showed high iron in the oil. Living in a hot climate, I had no worries about changing to 5w30. It has solved the wear problem and any mpg loss is so tiny I could never measure it.

0W-30 Oil
 

Just changed to Castrol 0W-30, we'll see how she does. I've had great success with this oil on my other cars.

I'm a fan of 0w-30 personally, for daily driving.



The manual says the 0w-20 oil is spec'd to run at 73psi at 6000rpms at 176F. So I'm going to assume that's a reasonable target for pressure. However we know that these cars, even in daily driver, run the oil hotter than 176F so that means the pressure is often below the ideal pressure as stated in the manual if staying with the 0w-20.


YMMV.

Resurrecting my own thread...

Time for a second change with 0W-30 and... I can't find any, other than Mobil1! I was hoping to try Castrol but now it seems they're all going to 0W-40...

So, I went ahead and used Mobil1 but now I don't know whether to stay with 0W-30 Mobil1, or try 0W40, or 5W-30...

Sigh...

STOP IT!



You're just confusing the newbies even more - :rolleyes:


humfrz

Are you really struggling to find 0W30? Catrol, Amsoil, Red Line, Motul, Shell, etc.
It's a quick google/amazon search.

So far, the only place I can find 0W-30 is at Walmart and even then it's just the 5qt. bottles. I was trying to avoid purchasing online right now because I'm kind of between houses now so arranging to be at my house to watch for delivery is a PITA. I guess in the future I'll have to go online...

https://www.oreillyauto.com/search?q=0w-30

https://shop.advanceautoparts.com/we...ExactFit=false

https://www.pepboys.com/search/?text=0w30

Any gas station may randomly have 'em.

The 0w-20 is recommended in large part because the AVCS uses the oil to do its thing. There are very fine tolerances involved and the thinner oil is designed with that system in mind. All vehicles are tending towards lighter oils as they become more efficient and have tighter tolerances and some sort of variable valve control.

The OP's anecdote is just that- anecdotal. The engineers who made the FA20 engine know a lot more and made 0w-20 the recommended oil for a reason. The engine in this car bears little resemblance to your dad's car back in the day and a lot of what he used to do will shorten the lifespan of your 86 today.

Subaru has been doing variable timing way before 0W-20 became so popular. For example there were Subarus with AVCS in 2008 and the owners manual lists all the way up to 10W-40 as an option and 5W-30 standard. Obama made 0W-20 popular along with any other BS thing that gives someone 0.0002 more MPG out of desperation. If it messed up the timing then manuals for other markets wouldn't even list 5w-30 as an option.

I just recently decided to change oil weights again (still sticking with Mobil1)..I went to 5W30 at 15K miles for better heat tolerance of occasional track days. However now at ~55K miles, I recently bumped to 0W40, not for better heat tolerance/viscosity, but rather a little bit better cold start pumpability. I live in a place where it's not unheard of to hit -10 deg F in the winter, and still push high 90s+ in the summer.

I'd also read on BITOG that the gold cap/Extended Performance versions of Mobil1 were the ones to get, as that particular additive package contained more cushioning metals than the 'standard' one, and I think the PDS backs that up if I recall correct. So I'd been using 5W30 XP, but I haven't been able to find it yet in the 0W40 version - just standard 'Mercedes spec' oil. I wonder what I'm giving up...

0W-40 is thicker than 5W-30 at all temperatures. How does it pump better in cold temperatures?

Where is this information about AVCS published? There's nothing magical about the system. Ports, valves, check valves, apex seals...

OTOH, the owner's manual specifies 5w30 and the Japanese one goes even thicker.

Can you provide some information how 0W-40 is thicker than 5W-30 at all temperatures. At very cold temperatures 0W-40 is thinner that's why it is listed as 0W.


I have been using 0W-30 for about 40k and according to my oil analysis my engine is in great condition. I recently made a switch to 0W-40 at the start of summer, I will post that oil analysis on this thread for comparison. I also spoke with at Mobil 1 on the phone to get more info before I switched to 0W-30. Also on their website they listed 0W-30 as being an approved oil for the FA20. I've had the FRS for years and logged 78k, using mostly 0W-30. I suggest doing the research yourself and taking everything into account before switching oil, rather than just doing what others say or sticking to the manual's 0W-20. The right oil for you may vary depending on your climate and application.

Plugged the mobil specifications in here, https://widman.biz/English/Calculators/Graph.html at -4f 0w-40 is thinner than 5w-30.Oops:bonk:

SAE Grade 5W-30
Viscosity @ 100ºC, cSt (ASTM D445) 11.0
Viscosity, @ 40ºC, cSt (ASTM D445) 61.7

SAE Grade 0W-40
Viscosity @ 40ºC 70.8
Viscosity @ 100ºC 12.9


Mobil only lists MRV for the 0W-40 and not the 5w-30. I think the real comparison for oil pump ability when cold is MRV and CCS from my understanding.