10W-50 oil in BRZ?

[spcmafia]

Originally Posted by ZDan

It doesn't have to be "experimenting", you should just pick viscosity based on max operating temperature and overall usage. If operating temp is 270F at the track and you don't drive on the street, 10w50 might make sense. Not so much street/track tho... FWIW I've been running 5w30 street/track with no cooler, temps up to 275F at the track. Might go to 0w- or 5w-40 this year...



Highly doubtful this is needed. My BRZ is the first car I've tracked a lot that didn't use any oil at all at the track. Typically I see 5000 street miles and 4 track days (~2hrs) between changes and I've never had to add oil between changes. In another thread somebody mentioned they added a catch-can and then removed it as it collected next to nothing. These engines are pretty good at containing the oil under track usage.


For me, I just swap trans and diff fluid out every season or two, never bothered to try to measure temps of these fluids. You could, but then it's the kind of thing where if you see the temps you may then think you "need" a trans cooler and a diff cooler. In reality you probably don't...

Upon further research, because the concept of 10W-50 was so new to me, there have been other recorded Forum cases of people using it, the more you know I guess. So I would agree is not actually experimenting. Though the option of an oil cooler might still make a little sense if not switching oils between track sessions, but that would be the prerogative of the owner.



What I meant with checking other fluids, is the fact that OP made it sound like he lives on the edge and so does the car. If you're constantly hammering the car you should probably shorten, or keep in consideration, the time between other fluids such as brake and LSD or even transmission. But I hope OP does the common recommended items for when you start tracking the vehicle.

[KillerBMotorsport]

Originally Posted by ZDan

It doesn't have to be "experimenting", you should just pick viscosity based on max operating temperature and overall usage.

That might be true for some fixed viscosity base fluids, but with a modern synthetic multi-grade it isn't. Any decent oil is going to have a working maximum temperature well beyond what a 'safe' limit is on an FA engine. There are much more powerful engines out there in performance oriented cars that use 0w20 without issue. The BRZ/GR is no different.

You use the oil the engine was designed for. Get a baseline, and go from there to optimize for your specific use and conditions. Even in the same region, oil that works well for me' my commute and event types, is very likely not going to be the most ideal brand/weight for the next guy. There's no one right answer here.

Originally Posted by ZDan

For me, I just swap trans and diff fluid out every season or two, never bothered to try to measure temps of these fluids. You could, but then it's the kind of thing where if you see the temps you may then think you "need" a trans cooler and a diff cooler. In reality you probably don't...

It's easy enough to establish a baseline of normal and watch it from there. Obviously, as power, mods, driver skill expand beyond 'typical' so too will these temps. The tell-tales stickies are nice, but again if you want to know your fluid is still within good working parameters (not contaminated, sheared down excessively, etc.), send out a sample.

I agree, I see far more oil coolers installed on cars 'because racecar', few know what their oil temps are, and even fewer knew what they even were before installing it. If you really want to be 'because racecar', you only add complexity (DNF potential), weight, and costs, when it's necessary AND going to payback in measured performance and/or reliability improvements.

[ZDan]

Originally Posted by KillerBMotorsport

That might be true for some fixed viscosity base fluids, but with a modern synthetic multi-grade it isn't.

The best modern synthetic multi-grades still have viscosity decreasing with temperature, which is perfectly normal. At 275F, 0w20 is going to be a LOT thinner than it is at 220F.



At 220F, 0w20 is ~7.5 cSt. At 275F, it's below 5 cSt.
Running a 40-weight oil you'll be back at close to 7.5 cSt at 275F. I've been running 5w30 in track season, may move to 5w40 this year...

If running for decent amount of time at higher temps, probably a good idea to run something thicker than 0w20... But 10w50 may be overkill!

I see far more oil coolers installed on cars 'because racecar', few know what their oil temps are, and even fewer knew what they even were before installing it. If you really want to be 'because racecar', you only add complexity (DNF potential), weight, and costs, when it's necessary AND going to payback in measured performance and/or reliability improvements.

100% agree!

[Tokay444]

What do they spec in this exact same engine in the cup car?
Holy FUCK! It’s 5w50!
https://www.blauparts.com/blog/toyot...g-ravenol.html

[ZDan]

Originally Posted by Tokay444

What do they spec in this exact same engine in the cup car?
Holy FUCK! It 5w50!
https://www.blauparts.com/blog/toyot...g-ravenol.html

This should be no surprise. If running track-only and you want viscosity in the range it is for "normal" 190F-220F temps, guess what? You need 50-weight to get there.

However if you are running limited sessions on track in your street car and don't want to change oil before and after *every* track event, maybe 5w30 or 5w40 is a better choice...

[Tokay444]

It isn’t a surprise to me.

[lapsio]

Originally Posted by KillerBMotorsport

What is this? I want it D:

Do those stickers show current temp or max peak? My MX5 NB doesn't have oil temp gauge and I want to see what temps I'm getting on track. it'd be awesome to just stick it on oil pan or somewhere.

[x808drifter]

Originally Posted by ZDan

The best modern synthetic multi-grades still have viscosity decreasing with temperature, which is perfectly normal. At 275F, 0w20 is going to be a LOT thinner than it is at 220F.



At 220F, 0w20 is ~7.5 cSt. At 275F, it's below 5 cSt.
Running a 40-weight oil you'll be back at close to 7.5 cSt at 275F. I've been running 5w30 in track season, may move to 5w40 this year...

If running for decent amount of time at higher temps, probably a good idea to run something thicker than 0w20... But 10w50 may be overkill!

100% agree!

You keep throwing that graph up here but I have to ask where it's from.
Who made it?
The only other place I can find it is subaruoutback.org in a single post.
No reference to who came up with these numbers.
I also can find no other info online backing any of these numbers up.
Or for that matter, how thick any grade of oil should be above operating temps, let alone 270F.

Until then I am of the thought, run what the manual says until an oil analysis says otherwise.

[ZDan]

Originally Posted by x808drifter

You keep throwing that graph up here but I have to ask where it's from.
Who made it?
The only other place I can find it is subaruoutback.org in a single post.
No reference to who came up with these numbers.
I also can find no other info online backing any of these numbers up.
Or for that matter, how thick any grade of oil should be above operating temps, let alone 270F.

Found searching on 0w20 5w30 viscosity vs. temperature. It's just an illustration, the point is the same whether those curves are perfectly accurate or not. Different specific oils may have somewhat different curves, but the general trend is the same. Higher temperature, lower viscosity...

Until then I am of the thought, run what the manual says until an oil analysis says otherwise.

The point is that *any* oil is going to thin out as temperature goes up. At 270F, if you want your oil's viscosity to be closer to what the factory-fill 0w20 is at normal operating temps (~190F-220F), you'll need to run heavier oil. This point is true whether or not the curves posted are 100% accurate. A 30-weight oil is going to have higher viscosity at 270F than a 20-weight, and 40-weight higher still.

What the manual specifies doesn't really apply if you're tracking at 270F+ oil temps. But some manuals still encourage use of thicker oils at higher operating temps...

[DrinkenBRZ]

Originally Posted by x808drifter

You keep throwing that graph up here but I have to ask where it's from.
Who made it?
The only other place I can find it is subaruoutback.org in a single post.
No reference to who came up with these numbers.
I also can find no other info online backing any of these numbers up.
Or for that matter, how thick any grade of oil should be above operating temps, let alone 270F.

Until then I am of the thought, run what the manual says until an oil analysis says otherwise.

You can graph it yourself on Widman.

[x808drifter]

Originally Posted by ZDan

Found searching on 0w20 5w30 viscosity vs. temperature. It's just an illustration, the point is the same whether those curves are perfectly accurate or not. Different specific oils may have somewhat different curves, but the general trend is the same. Higher temperature, lower viscosity...



The point is that *any* oil is going to thin out as temperature goes up. At 270F, if you want your oil's viscosity to be closer to what the factory-fill 0w20 is at normal operating temps (~190F-220F), you'll need to run heavier oil. This point is true whether or not the curves posted are 100% accurate. A 30-weight oil is going to have higher viscosity at 270F than a 20-weight, and 40-weight higher still.

What the manual specifies doesn't really apply if you're tracking at 270F+ oil temps. But some manuals still encourage use of thicker oils at higher operating temps...

I was trying to point out that while you are correct that oils thin as they go up in temp. Saying you need to run so and so weight is 100% BS without actual proof backing that up. Which is why I asked where that graph came from.

I will take a look at the Widman site after I get Home from work and Update this post then.

[ZDan]

Originally Posted by x808drifter

I was trying to point out that while you are correct that oils thin as they go up in temp. Saying you need to run so and so weight is 100% BS without actual proof backing that up. Which is why I asked where that graph came from.

100% BS? "Actual proof"?

FTR I don't think I've said "you NEED to run XwXX!". I've said that if you operate for extended periods at 270F+ as I do, it's probably good idea to run something thicker than 20-weight. I don't think this is a radical idea...

The viscosity of a 20-weight oil at 270F is going to be a LOT less than it is at normal operating temps of 190-220F. Running 30- or 40-weight at 270F is going to get you closer to what the viscosity of the factory-fill 0w20 is at normal street oil temps. Personally, I've been running 5w30 during track season, may go to 0w40 or 5w40 this year.

Feel free to run 0w20 at 270F while waiting for "actual proof" though!

[KillerBMotorsport]

Originally Posted by lapsio

What is this? I want it D:

Do those stickers show current temp or max peak?

They are tell-tale stickers, so they show the highest temp. You can get ones that show current temp (they aren't as accurate), but I don't see the need to crawl under the car regularly while driving, in traffic, or at an event. If I were, I'd just use an IR thermometer or IR camera as it would be far more accurate.

This is just another tool for thermal management. We have them in various places in the engine bay as well They came from McMaster-Carr, but you can probably find them in other places too.

Originally Posted by x808drifter

I was trying to point out that while you are correct that oils thin as they go up in temp. Saying you need to run so and so weight is 100% BS without actual proof backing that up.

^ This 100%

I see people in here searching for the couple examples that fit the narrative they want to believe, but that's just not how science works. Blackstone Labs already has over 80 results for the BRZ FA24 and thousands of FA20 results from Gen 1. If you really want to know what oil to run. Talk to these people. Don't base your choice on 'because racecar'.

Originally Posted by x808drifter

Which is why I asked where that graph came from.

I will take a look at the Widman site after I get Home from work and Update this post then.

There's a ton of these graphs out there. They all follow similar trends, so you're not going to find much variation unless you veer into 'marketing' graphs.

I see that graph and it shows STARK difference between the weights. Especially when targeting the ideal 210°-240° range. The 50 weight oil is going to be similar to COLD 20 weight. Which of course, explains why the pressure goes up; viscosity is a measure of resistance of a fluid to flow. You want to know how much less oil you're putting on the bearing when your flow resistance doubles? Do the math. It doesn't matter how hard you push on the oil (pressure), but it definitely does matter if you're getting enough on the load surfaces.

I'm going to be doing a bunch of oiling system testing as we do more testing and development work with our mule. I hadn't planned on doing anything with changing viscosities, because it's such a pain to do. With the EJ engines (or any engine for that matter), you change grades and see measurable differences in power, pressure, and flow.

[KillerBMotorsport]

Originally Posted by ZDan

1 at 270F+ as I do,

Where are you measuring your oil temps? OEM sender?