Quickie: 0w20 vs 5w20 / 5w30

[Gary in NJ]

I know this might seem waaaay out there, but why not run what the factory (you know, the one that spent millions of dollars and thousands of hours testing this very same engine) recommends. Remember, they have to warranty the engine. The do have a vested interest in the longevity of your engine.

I'm fairly certain that they gave a bit more thought to this then the collective here has. I know, I'm crazy.

[fooyc]

Dennis,
ya agree those 300v is good. I hv it in my current STI 15w50 as well as in another endurance track car. as for the 5w50 so far is ok car will not feel dragging..... may be the 15w50 will be too thick for a N/A, but the Honda Civic (FD2R) like it. Or may be the NEW FB20 is diff from the old EJ207??

Here when we track the car in noon time the oil temp can easily went to 120+degC some time can touch 130C, W/ the 300v 15w50 oil press still hold at ~ 2par (w/o engine load).

BTW, my GT86 don't hv any warranty from local Toyota dealer. as both 86 & STI are a JDM (bring in by used car dealer).

[kuhlka]

There was a pretty extensive thread on NASIOC a while back discussing using various non-recommended viscosities in engines. The consensus ended up being increased engine wear and tear because the oil pump and ports aren't designed to handle thicker oils. Think about it. 0w20 is like you sucking water through a straw. Now put 10w40 in and it's like sucking a thick milkshake through the same straw. Increased pressure on the pump and the oil is flowing through the engine slower which means your internals aren't getting lubricated as quickly. That's why others have seen a big power loss when running thicker oils.

Long story short, do your research before increasing viscosity.

[Mikem53]

Originally Posted by kuhlka

Long story short, do your research before increasing viscosity.

or follow the owners manual.

[Suberman]

Originally Posted by empower-auto

Hey guys, I have a quick one here and searching isn't really giving anything concrete.

Other than less efficiency is there any issue in running a 5wXX? - especially in a climate like mine where it gets very cold. (I use a block heater / properly warm up the car in the winter)

The other thing too - I change my oil and filter more frequently than most people and it gets extremely expensive when using premium 0wXX oils as they are typically 30-40 % more expensive than a comparable 5wXX of otherwise equal specification.

Yes, that 0W number is the one that counts. Use it.

[Suberman]

Originally Posted by empower-auto

You know what a block heater is right?

Anyways, this is the first vehicle I have owned that has ever wanted 0w20 oil. My previous daily driver was a Mazda 3 (2004 2.3L) and it behaved well all winter long even in some more of what you would consider extreme temperatures. I used 5w30 or Castrol 0w30 in it .. however the 0w30 led to some SEVERE oiling issues later on and I went back to a better oil.

Also, I don't allow a 7,500 mile interval myself. I typically change between 3,500 and 5,000 (max) miles and am very anal about using a good oil filter - which usually gets changed more frequently than the oil.

Canadian market specs 8,000 km or six month oil changes.

[Suberman]

Viscosity is not relevant to bearing protection. Oil protects bearings due to hydraulic pressure developed by rotation shear effects. The bearing floats on an oil wedge in similar fashion to a power boat planing over the surface of the water.

The W viscosity rating is very important for cold start and cold running. The main viscosity number should be used for all other engine protection considerations. Heavier viscosity may be desirable for extended track use, otherwise 0W 20 is the only oil to use.

[bluesubie]

Originally Posted by fooyc

Dennis,
ya agree those 300v is good. I hv it in my current STI 15w50 as well as in another endurance track car. as for the 5w50 so far is ok car will not feel dragging..... may be the 15w50 will be too thick for a N/A, but the Honda Civic (FD2R) like it. Or may be the NEW FB20 is diff from the old EJ207??

Here when we track the car in noon time the oil temp can easily went to 120+degC some time can touch 130C, W/ the 300v 15w50 oil press still hold at ~ 2par (w/o engine load).

BTW, my GT86 don't hv any warranty from local Toyota dealer. as both 86 & STI are a JDM (bring in by used car dealer).

If you have an oil pressure gauge, you can fine tune your viscosity at the track with oil pressure. There have been a few uoa's on 0W-20's and they are doing very well on street driven cars. There's also one floating around here on Motul 300V 0W-20. Keep in mind that the 86's engine was built with xW-20 in mind. The thickest that I would go is 5W-30 unless you have a built engine that has bearing clearances that call for a thicker oil. And if you use an oil that is very shear stable like 300V, you don't have to worry about it thinning as much.

Originally Posted by kuhlka

There was a pretty extensive thread on NASIOC a while back discussing using various non-recommended viscosities in engines. The consensus ended up being increased engine wear and tear because the oil pump and ports aren't designed to handle thicker oils. Think about it. 0w20 is like you sucking water through a straw. Now put 10w40 in and it's like sucking a thick milkshake through the same straw. Increased pressure on the pump and the oil is flowing through the engine slower which means your internals aren't getting lubricated as quickly. That's why others have seen a big power loss when running thicker oils.

Long story short, do your research before increasing viscosity.

I've been on nasioc since 1999 and don't recall such a thread about a consensus regarding thicker oil causing increased wear. Actually, I don't think there is a consensus about any oil on any web site. I do believe that you should go as thin as possible and only as thick as necessary for your application, but a turbo EJ engine is a completely different animal. Up until model year 2011, Subaru recommended 5W-30 for fuel economy and required thicker viscosities in higher temps with grades up to an xW-50 being allowed in severe conditions. My owner's manual allows 10W-40 down to -4F. A thin 0W-40 or medium 5W-40 is probably perfect for an EJ turbo with a few or little mods.

The BRZ/FR-S manual does allow thicker viscosities in certain condtions, although they don't define the conditions or the thicker viscosities like the older Subaru manuals did.

-Dennis

[kuhlka]

Originally Posted by bluesubie

If you have an oil pressure gauge, you can fine tune your viscosity at the track with oil pressure. There have been a few uoa's on 0W-20's and they are doing very well on street driven cars. There's also one floating around here on Motul 300V 0W-20. Keep in mind that the 86's engine was built with xW-20 in mind. The thickest that I would go is 5W-30 unless you have a built engine that has bearing clearances that call for a thicker oil. And if you use an oil that is very shear stable like 300V, you don't have to worry about it thinning as much.


I've been on nasioc since 1999 and don't recall such a thread about a consensus regarding thicker oil causing increased wear. Actually, I don't think there is a consensus about any oil on any web site. I do believe that you should go as thin as possible and only as thick as necessary for your application, but a turbo EJ engine is a completely different animal. Up until model year 2011, Subaru recommended 5W-30 for fuel economy and required thicker viscosities in higher temps with grades up to an xW-50 being allowed in severe conditions. My owner's manual allows 10W-40 down to -4F. A thin 0W-40 or medium 5W-40 is probably perfect for an EJ turbo with a few or little mods.

The BRZ/FR-S manual does allow thicker viscosities in certain condtions, although they don't define the conditions or the thicker viscosities like the older Subaru manuals did.

-Dennis

It may have been IWSTI or another forum linked from there, but the best I could find in a quick search - http://forums.nasioc.com/forums/showthread.php?t=499177

If I find the other thread, I'll post up another reply, but one of the forum members went pretty in-depth about brand comparisons, track vs street, etc and basically said the only time you'll need to consider changing weight from the manual's recommendation is if you're running long races or for extended periods in a very hot environment, like Death Valley hot. If you're doing that, you should have an oil temp gauge like you mentioned above. Most people aren't running in extreme environments and they shouldn't worry about changing weights. He also cited and showed various examples of engines which ran heavier weights and ended up causing engine damage over time. It wasn't pretty, but it was pretty informative.

My POV after owning around ten cars and four motorcycles is to just stick to the stock weight and go with a really good quality full synthetic and oil filter. Better to spend an extra $20 per oil change than risk thousands of dollars in engine damage. IF the manual recommends a specific weight for hotter or colder conditions, I'd say go for it, but otherwise stick to 0w20. Keep in mind turbo cars also share their oil with the turbo, so that tends to cook the oil faster than NA.

[fooyc]

yeap... best to get oil press & oil temp gauges to monitor the oil performance.

also in my country is not easy to get a good 0w20 oil.

[SXE10]

www.motul.com/MY/en = good 0W-20

[bluesubie]

Motul 300V 0W-20 from Zhapalang Motorsport:

http://motul-malaysia.blogspot.com/p/where-to-buy.html
http://www.zhapalangmotorsport.com/2...synthetic.html
:happy0180:
-Dennis

[garfull]

what about 0W-30

[zoomzoomers]

Good stuff...

On a tangent. I'm on my 3rd fill of oil. 1st factory, 2nd Royal Purple 0w20 and now my 3rd another fill of RP 0w20. When I replaced the factory fill my motor took a solid 6 quarts of oil, which I though was a little strange since the manual lists 5.4 quarts (is it?). Anyway, on my most recent change the motor took another solid 6 quarts. Have any of you guys out there noticed this? Or is my motor just got a slightly larger oil pan than what the factory states?