10W-50 oil in BRZ?
 

So I dropped my BRZ for regular service after 10k km which is fairly low interval but I'm hammering my BRZ fairly hard and tracking it quite often, so guys at Subaru recommended to check in every 10k or even less instead of 15k which is recommended by manufacturer. Since they know how hard I'm hammering and tracking it like it's stolen, and since summer is coming, they asked me if I want some more track ready oil, to which I replied "sure bud". I thought they'll pour some 0w-40 or something but they put Rockoil 10W-50 competition.

And now I'm like holy f*ck that sounds extreme. Does anyone have any experience with such oil? To put it in some context - I do indeed hammer my BRZ daily on my way to work (which unfortunately is really nice and engaging :D). On average when I'm arriving to my work parking lot I need to make few cooldown laps around building because I'm arriving with like 120 degrees oil. In fact I rarely see my oil to sit below 110 deg apart from rare occasions when I'm driving with family and have to pretend I'm responsible person.

But still difference between 0w-20 and 10w-50 sounds like entire universe of difference at least according to my (probably not so good) understanding of engine oils.

I am no expert on this, but from all the digging Ive done on oil for this chassis, 10w50 is ok to run in this car. Many have gone the 5w30 route for daily driving. Some even 5w40 or 0w40, especially when boosted. In one make races, or GT endurance cars, Toyota had them running 10w60 racing oil. If you beat on the car as much as you say, 10w50 seems just fine. DO NOT keep running it in cold weather. Youre in Poland so 5 degrees Celsius or less. If you are often driving when its below 5*C, you may want to switch to a 5w40. And do not beat on it when the engine is cold. Get 40*C in the oil first.

I know, that's something I'm really strict about. 80 deg, not less before real hammering. It's better safe than sorry.

Ok I guess I feel reassured. I'll most likely get different oil for winter anyways but good to know that it shouldn't damage anything in summer. Luckily I keep car in underground garage so it never actually drops below 0 where I keep it. Always around 8 deg here.

10-50 seems excessive. I don't think it will be a big deal, maybe be a bit careful to get some temp into it before being hard on it.

On a stock engine, this is a bad idea. Will your oil pressure go up, heck yes! But your oil flow will absolutely go down. To run heavy weight oil, the engine needs to be properly built for it. There is a stark difference in the flow dynamics of 0w-20 vs 10w-50. Hot temp characteristics are going to be poor, but the base going from 0-to-10 is worse.

The right thing to do here is send your oil out for analysis. Know what is going on with internal wear, then bump the viscosity up one step, then check again. Don't be surprised if the best results are obtained by the factory recommendation. Many, many times we hear of tech giving outlandish recommendations all the time with no clue, and definitely no thought to actually testing results from the recommendations they give. Tread lightly!

The only time I would consider swapping oils is if you're observing severe temperature swings between your daily driving and track time. The right thing to do there, is use the best oil for each job. Change the oil before a track day and bump a step up (not double). Based on temperature/flow profiles a decent bump in normal temperature (say +25-50 degrees f) with a one-step higher grade of oil, will give you very similar flow rates to the thinner spec during daily driving temps.

Ideally, you right the proper oil for the conditions your car will see 90% of the time.

I’ve run 50wt with UOAs in these engines off and on since 2016 with never an issue. You’ll be fine and it’s probably wise to step up to that weight for summer tracking if you’re experienced enough to push the car hard on track and aren’t running and oil cooler. I’d reduce your oil change interval though. Maybe down to 6000km. Tracking dumps a lot of nasty in the oil and is worse with how rich direct injection platforms run.

Unnecessary in my experience.

I have tracked with 0W20 oil the entire time (both without and with oil cooler). I don't use special race oil either. Have not seen any issues with oil pressure since I added a means to monitor it.

My oil analysis from multiple tracking scenarios over a variety of climate conditions (very hot to cold). Based on the results, the oil is good for at least 2 track days and a full mileage interval (7500 mi/12000 km). This will vary based on your car's setup and the demands of your local road courses.

Two heavy duty case scenarios both returned just fine for oil and engine health:

• 2 track days /w 8600 mile interval (no oil cooler, winter only tracking): normal wear characteristics, normal oil & filtering characteristics, remaining total base number (TBN) 2.5
• 3 track days /w 7500 mile interval (oil cooler, e85, summer and winter tracking): normal wear characteristics, normal oil & filtering characteristics, remaining TBN 4.6

I've done some digging around the oil-club.de forum.

It seems this is an excellent Group IV and Group V synthetic engine oil (Ester and PAO based) with a lot of ZDDP and Molybdenum (really good for reducing friction between 2 metal surfaces). Mind you, it does contain a higher amount of "ash" and it might affect (clogging possibility) the stock catalytic converter:

https://oil-club.de/index.php?thread...carbon-10w-50/

https://oil-club.de/wcf/index.php?at...on-10w-50-pdf/

As @Westen86 already mentioned, avoid regular usage in sub-zero ambient temperatures (°C) and ensure proper warm-up is achieved.

I personally use Ravenol RRS 5W_50 (it's also used by Gazoo in their 86 cup cars) or RCS 5W_40 (is more viscous than Motul 300V 5W_40).
Here's also a post I made, why I use the aformentioned engine oil (mind you, my engine is no longer stock):

https://www.ft86club.com/forums/show...99#post3502099
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TL : DR - ensure proper warmup before putting the foot down. The oil you have in your engine is excellent :)

50 is for non stock motors that are in a 100% racing environment. Any less and it’s not the correct oil.

Doesn't a thicker oil make the motor run hotter than a thin oil?

Summer weather in Poland seems to average at 70-80*F. Are you sure you need anything above a 0w30?

Isn't it right that most oil viscosities thin out to the same degree when at operating temperature?

Aren't the VTC's designed to operate with a specific viscosity of oil, otherwise might not work properly? Have seen this claim made a couple times.

Probably better off buying a more affordable off-the-shelf oil and changing it often, rather than running it 10-15,000 miles.

"For a dual-purpose car, engine oil needs to be at least 220 degrees F to burn off all the deposits and accumulated water vapor. For every pound of fuel burned in an engine, the combustion process also generates a pound of water! If engine sump temperatures rarely exceed 212 degrees (water's boiling point), the water will mix with sulfur (another combustion by-product) and create acids that can eventually damage bearings."

-Motor Trend acticle

Heat kills oil. Not time, not friction. Whats happening is a trade-off between heat deterioration and oil life. What you want is maximum protection for the amount of time between oil changes. Is 0w20 just fine for a race car? Yes, but for how long? Is 10w50 just fine for a race car? Yes, but for how long?

I dont think you are ever reaching a point with 10w50 where you are maximizing its capabilities. A thinner oil would protect your engine better GIVEN A STANDARD OIL CHANGE INTERVAL. Is 10w50 just fine for your car? Yes, but...

Yeah well I kinda noticed that it does indeed seem to run a little bit hotter, maybe due to a bit lower oil flow mentioned above, but the idea is that such oil should protect engine better at such temps and degrade less right?

I meant 10k km interval which is 6200 miles. Actually this time I changed oil after 5500 precisely.

So I should change oil more frequently when using 10w50 or less frequently?... "standard" interval was never considered but I don't have anything against reducing this interval below 10km / 6k miles like idk, change every 5k/3k sounds acceptable to me if it'd be recommended.

Standard Mustang GT 5W-20. Track pack? 5W-50. Exact same engine.

The higher weight provides a higher load capacity, but an engine really needs to be properly built for that, with increased bearing clearances. Otherwise, you are restricting oil flow (which is why oil pressure increases with heavier weight oil).

If you think it's all about power, think again, Nascar runs 0w-5 weight oil under some VERY harsh conditions, and also at much higher temperatures than we're seeing. It's not about what someone says is the better oil to run, it's about what oil the engine was designed to run with.

If you're going to experiment with it, one step at a time. It safest. Not only that, if you had an issue and brought your car in for warranty and they figured out you were running the wrong weight, you will very likely be denied warranty.

So the Coyote was designed to run two distinctly different oil weights.

Subaru technicians put this oil in so they can't void my warranty. Worst case it will be covered by their insurance as technician error. That's how it works here. I mean if they wanted to put this oil on my responsibility I'd have to sign paper stating that it's on me but I didn't sign anything so it's on them. It's authorized / certified Subaru dealership and workshop. Not random barn garage so even if the worst happens I'm covered. But I'd still prefer if worst didn't happen, to avoid trouble both for me and them :D

So since I picked up this car after oil change I started to record OBD-II traces from my rides from work to home to discuss them later with Subaru and ask if it's okay but I also want to get second opinion on that so...

Today out of nowhere snow fell in Warsaw and temps dropped to 0 because weather decided to prank us. It came to all of us as surprise tbh. But it means I was able to collect 3rd and final OBD-II trace that represents 3rd driving scenario - slippery conditions. As such I have 3 traces from 3 driving scenarios which more or less describe all my driving scenarios:

- hammering on back roads / outskirts / highways
- driving through city centre
- driving through city in terrible slippery / rainy / snowy conditions

Here are screenshots from traces. All of them have the same legend:
green - oil temp
red - water temp
yellow - air intake temp
blue - rpm

green - speed
red - acceleration in G's

Day1 (back roads / highways): max 125°C
http://lapsio.lapsio.dev/public/inet...s/10w50-4.jpeg
http://lapsio.lapsio.dev/public/inet...s/10w50-3.jpeg

Day2 (city): max 115°C
http://lapsio.lapsio.dev/public/inet...s/10w50-1.jpeg
http://lapsio.lapsio.dev/public/inet...s/10w50-2.jpeg

Day3 (snow): max 118°C
http://lapsio.lapsio.dev/public/inet...s/10w50-6.jpeg
http://lapsio.lapsio.dev/public/inet...s/10w50-5.jpeg

So if I were to increase by one step what oil would you recommend? Please consider traces from daily driving shown above if possible.

I'm a bit puzzled because this oil runs quite hot with my driving style, regularly near 120 and guys at Subaru asked me to report when it gets in 120-130 deg range because it may be unhealthy :c According to my observations I'd have to report it like 160 times during service interval or so lol.

An adverse consequence of the wrong viscosity oil is that the drag saps power output. I read that the AVCS (valve timing control) is very dependent on the proper oil pressure and flow. What effects are there if the oil is too thick?

I'm not familiar with this oil but even if it has a great additive package I'm going to say it's too thick for your engine and usage. I also don't think 125C for oil temp is that hot.

I don't know if our engines are designed for such a heavy 10W50 oil.

Also, hard street driving is much different (easier on the car) than actual tracking. I personally use 0W30 and feel that is sufficient. I doubt you'll find many people using anything more than a 40 weight oil on the forums.

Through all of this exercise the answer is the bigger the viscosity number doesn’t mean better. Stick with the manufacturers recommendations or at least close. 50 is double that. Makes zero sense.

The factory fill is there to meet EPA enforced fuel economy numbers. Guess who only cares how that your engine only lasts longer than the warranty so they can sell you a new one?

What do they tell you to run in the cup car with the exact same engine?

My well known engine builder who has nothing to gain by recommending an oil viscosity does not reccomend anything remotely close to 50. I’d listen to them over someone on the internet that thinks they know what they’re talking about.

True or false. The epa mandates fuel economy figures.

I don't think @lapsio 's driving conditions are anywhere near needing a heavy racing oil and that it could be worse for the engine in cold weather. This was a mistake made by the guy running the service desk at his dealership. Wouldn't be the first bogus recommendation I've seen by a dealership service advisor.

I would recommend trying a 0w30 or 0w40 euro blend. But I also think you're better with a 0w20 in freezing conditions for cold starts and fuel economy!

@lapsio you should look at BMW M3 bearing failure from that engine running heavy weight oil; this video from savagegeese (former member here) gives a good idea of what you might need to run. His example is in northern climate. Check the video at 10:00.

https://www.youtube.com/watch?v=ASAdkJydBFU

Most everyone is missing the point of the OP when he’s asking if he needs to have this newly installed oil replaced because of the grade. He does not need to and can safely run this oil through the summer, at least. Would a 0w40 or 5w40 be more ideal, yes. But, he can put that in in the fall. And advise the shop to stick with that going forward. He’s does track and will benefit from the extra viscosity.

Okay so my conclusions after watching video is that the first thing I need is oil pressure monitoring right? Because without that it's basically clueless guessing what could be going on.

Video here is quite extreme. though. I mean yeah I'm aware that 10w50 will be dreadful in sub zero but like I said I keep car in garage. Even though there was 0 outside yesterday, oil never really reached this temperature at any point to begin with. It was 8 deg in garage which is basically the same temp I have in underground garage in summer.

And it's acceptable for me to just never start car below this temp with such oil. That said I DO indeed think this oil runs hotter than 0w20 did and I have some doubts about that.

So to recap - according to my understanding oil pressure determines how well oil flows through engine so IF i find oil that within my operating temperatures during daily driving (which is around 110-120 C) has similar pressure to 0w20 which is what's recommended for grandpa driving at 90-100 deg C on oil (which I personally still see as "cold engine") then it means flow rate should be fine and I should be good to go?

Stop overthinking this.
Put the factory recommended oil in. (0W-20)
Your local "techs" are morons.

/end_thread

No, oil pressure do not tell you about oil flow since viscosity comes into play. With the same oil pressure and temp one oil can have 20% more flow than a different one. It's pretty common that oil temperatures goes up with a higher grade oil.

Without a 0w20 baseline, with pressure, and flow data there's no way to determine anything.

I would prefer to see oil temp taken at the sump. It's going to give you more accurate feedback for a couple of reasons. One, is that the temp is skewed because the OEM temp sender is post oil pump. Another reason is that we don't know yet if the ECU is modulating the oil temp displayed. Oddly enough, this is becoming a more common trend from the OEM. We've seen this in Porche, AMG, and even with the 2015 WRX. With the 2015 WRX you'd see a difference swing from 0-to-just over 20 degrees. Why is this done? I speculate that it's done as another layer of safety. Similar to how an OEM coolant gauge is really a course 3-position gauge.

Another thing I would recommend is sending oil samples out for analysis. This is a safeguard against going down a path that is detrimental to the engine. I wouldn't put too much weight into feedback from techs, we hear them give bad info all the time. If anything with a warranty is questionable, Subaru will send a regional tech (non-dealer affiliated) who will make decisions on coverage. He WILL point to the owner's manual if the oil gets tested.

Will sending current oil (10w50) after next change also indicate whether something was wrong? Or does it only show signs of wear if oil was too thin?

Besides I checked owners manual of my BRZ and it also mentions 5W-30 as officially acceptable oil. So I think I'll go with that then... At least nobody will void my warranty for that xD

Also wow I think this thread made me realize what does "hot oil" actually mean lol
https://www.ft86club.com/forums/showthread.php?t=91820

5-30 is a good, middle of the road choice.

It will indicate if there are issues one way or the other.

5w30 Subaru oil is what my local toyota/Subaru dealer put in the twins. Im not sure exactly why they chose that, probably because its the same as other Subarus.

yes, simply put.

oil analysis will test the fluid and report back with what's in it. there's always some expected levels of each type of metal, specific to different parts of the engine.

here's a sample of a report. i've always liked blackstone labs

https://schwarttzy.com/wp-content/up...1-782x1024.jpg

pay attention to the 'universal averages' and what they're pointing out in that report. excess wear indicates that something isn't right, or that would require different maintenance.

You are reasonably correct. FWIW you can probably run the 10w50 down to -10C and be fine. It’s overkill for a stock twin that isn’t seeing endurance racing, but just use it now that it’s in there.

I would think 10w50 would not be ideal for your situation. 120 deg C is not that hot and you are not keeping it up there for hours at a time. If you are NA I would run 5W30 and as stated above be careful until you oil gets to temperature (not coolant). My experience is, mine is turboed and I do run 0W40. Car does not get driven below freezing and our track days can be 32 degC plus. I am usually coming off the track after 20 min at 130 deg c or so.

I have not read what others have commented so far, but have you considered an oil cooler instead? There are dozens of pictures here of oil starvation and cavitation. 10W might be too thick for start-up and until fully warmed-up. If I were you, an oil cooler would be the first place to look into.

I will agree with you. Everyone is always stating that the “engine was designed for that weight” Not a correct statement. The engine was designed for a certain oil viscosity. This changes when you change the operating parameters(Temerature) of an engine. Another case in point is the 2GR-FE engine. In a Lexus it takes 0W20. In an Lotus Evora it calls out 5W40. Lotus does nothing to the engine except add a supercharger to it.

I already ordered Rock Oil Carbon 5w30 and scheduled oil change as soon as it arrives. Maybe I panicked a bit but idk. I've seen plenty of really extreme opinions about low tolerances in FA20 and oil flow issues on many various forums, including official Subaru forum. The same concerns which also were mentioned here. And it's kinda not the point. I mean - I wanted better oil to be able to hammer car harder without any compromises and considerations, not to actually drive more carefully due to oil flow concerns, problems with maintaining oil temps above 95 when it was colder outside etc. With 5w30 at least my only concern will be temps, which are easy to understand and control. Unlike oil flow and pressure which I can't control and monitor due to lack of gauges and tools in my brz.

At least I'm gonna have some comparison since I saw temperatures with 0w20, 10w50 and now I'll see how 5w30 behaves. I have all my current rides recorded using OBD and GPS so I'll be able to later compare temperatures. That said today I again reached 122 C (around 250 F) on my way to work and I'm a bit worried about oil flow soo... I guess I don't feel all that comfortable with that 10w50.

If temps will be worse with 5w30 then I'll revisit this topic and wonder what next. For now I guess I know what to do.