[mr.paul]

I firmly believe e oil threads and oil angst are never ending because it is one of the few items the average owner can "control". The rest of the workings are a mystery and everyone wants to think they can improve on what they have. Never mind that there are highly paid, multiple engineers devising this stuff, and the average office Joe hasn't got a clue. But he still wants to out guess the engineers.


I'm a firm believer in synthetic oil. I was selling the stuff when Mobil 1 was introduced in the 70's. At the shop, we did our own "unscientific" testing. We found that almost all vehicles got better mileage. Oil pressure went up a lot faster on cold (very cold) starts. The oil spouts would slide out of the can when you picked it up by the spout (remember oil cans and oil spouts?) And we could leave the cans of Mobil 1 out on the gas islands in the coldest winter days and they would still pour. Conventional oils wouldn't. After we got some experience with wear factors, everything was better with synthetic. We also learned that film strength had a lot more importance than just weight. Yet, there are still people that won't let go of old tractor and Harley feelings of heavier is better.


I became an Amsoil believer. The stuff was quite good to me and my engines. All my vehicles had well over 200k with no evidence of oil related failures or even much wear. I don't know who makes Subaru Synthetic oil, but if it is even near as good, I am confident that the specified oil will be great. I accepted a 10 year oil change package with the dealer, so I hope it is. I've personally never let anyone else change my oil in anything for my life so far until now.

I think the bigger factor may be how careful you are with the hygiene of the oil change. All the care in the choice of the oil goes out the window if the guy changing it is clumsy and introduces contaminates into the oil. Along with that, frequent cold, short trips are hard. Otherwise people, relax! Your oil is OK. 0w-20 is good for close tolerance mechanicals as thicker oil wont flow through there as easily. And better flow carries heat away more effectively. It is all about film strength.

 

[Leroy Lemon]

An oil weight question for the Canadian version of Ascent.

My maintenance manual (page 24) states that 5w 30 is “required” for all 2019 turbo models.
Yet my oil filler cap says 0w 20.

I’m not ready for the first change yet and will probably let the dealer do the first one.
However, I would like to make sure that I’m using the right grade when I do the job myself.

 

[Robert.Mauro]

Canadian...

Hi @Leroy Lemon, I'd ask Subaru Canada.

 

[tuanvo]

An oil weight question for the Canadian version of Ascent.

My maintenance manual (page 24) states that 5w 30 is “required” for all 2019 turbo models.
Yet my oil filler cap says 0w 20.

I’m not ready for the first change yet and will probably let the dealer do the first one.
However, I would like to make sure that I’m using the right grade when I do the job myself.

Hi fellow Canadian,

Even though the Maintenance/warranty booklet says 5W-30, the main Ascent Owner's Manual says 0W-20 (p. 487). I think that Subaru Canada forgot to update the Maintenance booklet with the Ascent in mind (it's the first Subaru turbo that uses 0W-20). But please let us know what they tell you if you call in.

 

[Trey T]

An oil weight question for the Canadian version of Ascent.

My maintenance manual (page 24) states that 5w 30 is “required” for all 2019 turbo models.
Yet my oil filler cap says 0w 20.

I’m not ready for the first change yet and will probably let the dealer do the first one.
However, I would like to make sure that I’m using the right grade when I do the job myself.

Being in a mild weather region, 0W or 5W oil weight doesn't matter much to me. For extreme cold weather, choosing 0W or 5W can be critical. Based on the given info provided, it's a safer bet to go with the 0W that's stamped on your engine as a primary source of information, and that the oil weight will allow you operate/start your engine in extreme cold climate.

I'm sticking with 0W full-synthetic.

 

[Leroy Lemon]

Had a chat with both Subaru Canada and my dealer's service department and both said 0w 20 synthetic is the grade to use.

 

[xydadx3]

We got a mention!

2019 Subaru Ascent long-term update: Easiest oil change ever

Maintenance is part of almost any vehicle ownership experience. If you're a DIYer, you'll love how easy it is to handle oil changes in Subaru's biggest SUV.

www.cnet.com

 

[Robert.Mauro]

We got a mention!

2019 Subaru Ascent long-term update: Easiest oil change ever

Maintenance is part of almost any vehicle ownership experience. If you're a DIYer, you'll love how easy it is to handle oil changes in Subaru's biggest SUV.

www.cnet.com

LOL, I saw that too.

 

[DKL]

Hello, new to the forums; 2021 Ascent owner as of 11/14/20

I owned until recently a 2017 Civic with the 1.5t engine, and the "best" oil viscosity was hotly debated on the Civic forums as well. One resource I came across:

540 RAT - Tech Facts, NOT Myths

540ratblog.wordpress.com

I don't take rat 540's word as gospel, but I think there's useful info in there. Some tidbits I found:
1. oil film strength and viscosity aren't correlated
2. If one had to choose an ideal weight for any modern engine it'd be a synthetic 5w30 - I'd have to agree with this
3. thinner oils pump faster and cool engine internals better, thicker oils maintain oil pressure better.

On the civic forums, some people thought any deviation from the manufacturer recommended 0w20 would cause the sky to fall, voided warranty etc.
So I did it anyway.
I submitted a number of UOAs; I tried Amsoil signature series "new" formulation 0w20, 0w30 and 5w30, QSUD (quaker state ultimate durability) 0w20 and the older signature series 0w30, all with 5k intervals. I also compared my results to other owners submitting UOAs with Amsoil, Mobil-1, QSUD, Honda OE (Idemitsu), Penz. platinum etc.
My observations:
Amsoil is good stuff (no, I'm not a dealer), but it's also one of the most expensive.
Amsoil 0w20, 0w30 and 5w30 all produced fantastic (low) wear metals, 0w30 being the best, but all very close. The new Amsoil formulation was definitely better than the old one. The wear metals with QSUD 0w20 weren't terrible, but were about twice as high as Amsoil.
The heavier oils almost always fall into the 20w range after 4-5k miles
I also have a Civic type r, and I ran Amsoil 0w30 and 5w30 and got great wear numbers
My opinions: I think the 0w20 oils are recommended largely for fuel economy ratings. The argument that they're required for the close tolerances (sic) I think is dealer BS. What they're trying to refer to is piston skirt, ring and bearing clearances.. and I don't think you can build an engine tight enough, allowing for thermal expansion, where it would matter if 0w20 was used. The thing would seize, idling in traffic. That being said, I'll plan on running Amsoil 0w20 in the Ascent at least until the warranty expires. It's a different engine, but it performed well in my Honda 1.5t. I'd definitely consider a heavier weight if I was towing for extended periods, or lived in a hot climate.
JMO, hope this helps.

 

[Robert.Mauro]

@DKL something to keep in mind are the differences in a horizontally opposed boxer engine, and an upwards I or V facing standard engine. There's some interesting differences in how oil pools, how it flows and how it needs to be pumped, in a piston-sideways, H4 or H6 configuration. Besides fuel economy, I wonder how much of that went into the consideration.

Anyways, I tow a lot, and I put my engine through a lot more abuse than towing creates, and I run the OEM Idemitsu Subaru branded 0W-20 oil, and expect no issues. At just shy of the 70,000 mile mark, I will do an oil analysis (November 23rd's oil change).

 

[ChrisWilliams]

Want to start some drama on oil weight ? Go to the Ram Hemi forum and start a thread 5w20 vs 5w30 in your truck lol

 

[Outback King]

Has anyone used something like a 0w-40 oil in their Ascent's engine? I would consider using a light 0w-40 like Mobil 1 or Pennzoil Platinum Euro (or PUP) in the FA24F myself because I like to play that way 👍

 

[Jim_in_PA]

Has anyone used something like a 0w-40 oil in their Ascent's engine? I would consider using a light 0w-40 like Mobil 1 or Pennzoil Platinum Euro (or PUP) in the FA24F myself because I like to play that way 👍

It's best to use the oil weight and specification that Subaru says is required...which is 0W-20.

 

[Outback King]

It's best to use the oil weight and specification that Subaru says is required...which is 0W-20.

Okay so you are not going to use 0w-40...

...has anyone else tried using it? That is all that I am asking. I am well aware of what Subaru recommends for oil usage as we have discussed it extensively over at SubaruOutback.org

 

[packout]

Okay so you are not going to use 0w-40...

...has anyone else tried using it? That is all that I am asking. I am well aware of what Subaru recommends for oil usage as we have discussed it extensively over at SubaruOutback.org

I do not recall any posting of anyone using that weight nor anyone indicating any interest in doing so.

 

[Merope]

What would be the aim and how would the effects be evaluated/quantified?

 

[Trey T]

Has anyone used something like a 0w-40 oil in their Ascent's engine? I would consider using a light 0w-40 like Mobil 1 or Pennzoil Platinum Euro (or PUP) in the FA24F myself because I like to play that way 👍

The 0W number is significant for the first 15min-or-so of engine running time. The -40 number is a critical number because the engine will experience that viscosity# at nearly 100% of the time. If you're going to deviate from 0-W20, their recommendation, and do not live in extreme temp area, then stick to 0W-30 or 5W-30. Subaru's user manual allow the -30 viscosity for nearly 6000miles (normal driving condition) for unspecify technical reason. Based on my interpretation, it implies you can do like 500,000miles (@ 6000mi change intervals) with 5W-30 because if you can do nearly 6000miles and not degrade your bearing surfaces, then you can do more.

Keep in mind that what Subaru propagate thru user manual is a policy with general standard. Policies do not translate to technical matters very effectively, and that's where we need to use our brain. But we should use 0W-20

 

[hokiefyd]

Note that the viscosity grades for oils (the "20", "40", etc.) represent measured viscosity ranges at certain temperatures (at 100*C, actually). Your engine oil is almost never at exactly that temperature. In fact, our engine oil very often never does get that warm (at least indicated on the dash-top display). Temperature will certainly vary throughout the engine (in the pan, in a journal, at the bearing surface, etc.), but we can go only with what we can directly observe, at least for a casual conversation like this.

But again, the grade number represents a range of viscosity units...it's not the viscosity itself. A 20 grade oil (such as a 0W-20 or a 5W-20) must have a viscosity of between 5.6 and 9.3 cSt (centistokes) at 100*C. At only 60*C, or 80*C, the actual measured viscosity of a 20 grade oil will be higher, probably in the 10-12 cSt range. The viscosity range of a 5W-20 will increase faster as it cools than a 0W-20 will. A 40 grade oil must have a viscosity of between 12.5 and 16.3 cSt at 100*C. Again, at lower temperatures, it'll be even higher than that. It's not like the engine will blow up with a thicker oil. Even a 0W-20 is way too thick at startup to be optimal (hundreds of cSt probably, depending on the temperature).

Subaru says clearly that a 30 grade oil is acceptable, but that a 20 grade oil should be used at the next opportunity. I believe they say this because 0W-20 was used during fuel economy certification and they're required by law to recommend the same oil be used during service. This is to avoid using something like a 5 grade oil for fuel economy testing and then filling and recommending a 30 grade oil for longevity.

Interesting aside: when 20 grade oils first started appearing, people would say that they're "thin like water", especially with a hot drain. They're actually not. Water has a viscosity of about 1 cSt at 18*C. At 18*C, when a 5W- or a 0W-20 is measured in the hundreds of cSt, water's at 1 cSt.

 

[Trey T]

Note that the viscosity grades for oils (the "20", "40", etc.) represent measured viscosity ranges at certain temperatures (at 100*C, actually). Your engine oil is almost never at exactly that temperature. In fact, our engine oil very often never does get that warm (at least indicated on the dash-top display). Temperature will certainly vary throughout the engine (in the pan, in a journal, at the bearing surface, etc.), but we can go only with what we can directly observe, at least for a casual conversation like this.

....

What's the temperature of your engine oil during normal operation?

 

[hokiefyd]

What's the temperature of your engine oil during normal operation?

Going only by the dash-top display, the oil temperature varies significantly. During colder weather, the oil temperature may never rise above 160 deg F, even on a 10+ mile trip. During warmer weather, it's usually up between 190 and 200 deg F. It may go up to 220 deg F or so during a long hill climb where engine speeds are elevated.

Engine speed is the biggest contributor to oil temperatures, at least in my experience. If I idle the car around in CVT mode all day, the oil temperatures may stay low for a while. But if I keep the engine spun up in manual mode, oil temperatures will rise quicker. Even in cold temperatures.

I would say "normal" temperature of our engine oil is about 190 deg F. Again, indicated by the dash-top display. Of course, temperatures at the bearing interfaces or just after will be much higher. Temperatures in the pan may be lower. I'm not exactly sure where in the system the temperature sensor is located, but that'd be interesting knowledge to have.