Running different oil weights for summer season (AutoX/Track)

[Teseo]

Originally Posted by strat61caster

My FA20 spun a bearing on 5w-30 during an autox, 117k miles, the last 40k miles were on 5w-20, first 75k we’re on 0w-20, sticking with 0W-20 for the second build. ymmv

Thats odd... I thought 5w-30 give better protection because it retain better oil presure

[Tokay444]

Run 0w40 Mobil1 FS year round and forget about worrying about oil.

[Tokay444]

Originally Posted by strat61caster

My FA20 spun a bearing on 5w-30 during an autox, 117k miles, the last 40k miles were on 5w-20, first 75k we’re on 0w-20, sticking with 0W-20 for the second build. ymmv

Without a shadow of a doubt, I can say the reason the bearing spun had nothing to do with the oil's viscosity numbers.

[strat61caster]

Originally Posted by Tokay444

Without a shadow of a doubt, I can say the reason the bearing spun had nothing to do with the oil's viscosity numbers.

.

[OkieSnuffBox]

Originally Posted by cmiovino

If it's just one a month, 0w-20 is fine. Just about everyone here running gen 2's runs 0w-20, including top-dog national level drivers. They push their cars hard.

I'd say part of that is actual national level drivers aren't worried about their warranty and don't care about dropping the pan to check for excess RTV.

Those guys operate at a different $$$$ level than us middle-class plebs for the most part.

Originally Posted by VoltsFRS2013

5W20 isnt that far off your OEM weight, and it's already in the manual in gray area fine print that you can run that weight anyways lol. That being said, I'd be changing your oil after every event if you're doing some hard hard driving.

Depends on which book you look at. It just says "USE 0W-20 Synthetic" Page 42 of the 2023 BRZ Getting Started Guide:

ENGINE OIL
Use 0W-20 synthetic, with one of the following specifications:
• API classification SN with the words “RESOURCE CONSERVING”, SN PLUS with the
words “RESOURCE CONSERVING”, or SP with the words “RESOURCE CONSERVING”.
• ILSAC GF-5 or GF-6A, which can be identified with the ILSAC certification mark
(Starburst mark).


https://techinfo.subaru.com/stis/doc...2306A_STIS.pdf


Page 382 of the 2023 Owners Manual says:

0W-20 synthetic oil is the required oil for optimum engine performance and protection. Conventional oil may be used if synthetic oil is unavailable.*: If 0W-20 synthetic oil is not avail-able, 5W-30 conventional oil maybe used if you need to add oil. However, you should change to 0W-20 synthetic oil at the next oil change

So they are saying use 5W-30 in a pinch, not they are suggesting running it full time.

https://ownersman.com/manuals/2023-S...-owners-manual

[soundman98]

but it's really only for warranty coverage.

we could all run 75w gear oil if we so desired, nothing is physically stopping us...

[OkieSnuffBox]

Originally Posted by soundman98

but it's really only for warranty coverage.

we could all run 75w gear oil if we so desired, nothing is physically stopping us...

Well it's also the spec they designed for which they designed the engine.

So run some 75w-140w probably have great oil pressure.

[removedonut]

0W20, 5W20, and 5W30 are all accepted oil weights (to run full-time, not just in a pinch) in the australian and japanese owner’s manuals. They have the same engines. The TMNA insistence on 0W20 is almost assuredly just for fuel economy reasons.

[Ernest72]

Just run 0w20 and change it more often, it’s not hard to do. My 16 BRZ is a commuter and I change every 5k, even though Blackstone said to go more. No track for me, if I was, I would just make sure I was not too far into my OCI (2000-3000) and then change it after the event.

[ruturaj001]

I am doing it, 5W30 for summer when I am doing track and autocratic, will switch to 0W20 in winter.

[Ernest72]

Someone needs to measure oil pressure on the same long sweeping turn on the track with both oil weights. I wonder if the thicker oil will actually lead to better oil pressure. Logic says it should but I wonder.

[strat61caster]

Originally Posted by Ernest72

Someone needs to measure oil pressure on the same long sweeping turn on the track with both oil weights. I wonder if the thicker oil will actually lead to better oil pressure. Logic says it should but I wonder.

Already been done on FA20.

https://www.ft86club.com/forums/showthread.php?t=91820

[RaceAddict]

Originally Posted by removedonut

0W20, 5W20, and 5W30 are all accepted oil weights (to run full-time, not just in a pinch) in the australian and japanese owner’s manuals. They have the same engines. The TMNA insistence on 0W20 is almost assuredly just for fuel economy reasons.

100% agree with that!

Like anything else you may read/watch on the internets, feel free to take anything I'm saying with a grain of salt, do your own research etc... but it seems to me that 0W20 being recommended as a one-size-fits-all solution is entirely down to EPA mandates and automakers striving to hit fuel economy numbers.

Here's an article from 2012, which I believe is a year after the 0W20 mandate came into play:
https://www.consumerreports.org/cro/...cars/index.htm

I'd suggest it has nothing to do with "tighter manufacturing tolerances" and everything to do with legislation.

And remember, the EPA doesn't care how long your engine lasts.

[Ernest72]

Originally Posted by strat61caster

Already been done on FA20.

https://www.ft86club.com/forums/showthread.php?t=91820

Looks like 5w30 is a good idea for hot weather tracking. I am street only so sticking with 0w20, plus I have two very good oil analysis going with 5k changes.