Re-evaluating 0w20 - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Guillaume · 05-20-2014, 09:49 AM

Quote:

Originally Posted by regal

The Subaru FA20T does have different pistons, they lowered the compression ratio. But the crank is the same so I don't think they would have changed clearances.

Why not? It's as easy as changing the bearing specs, even with the same crank.

mrk1 · 05-20-2014, 10:10 AM

I really don't see a reason to switch from 0-20. Sure its very thin but is thats what is recommended by the people who made the FA20. And I mean the FA20 that is in our cars not another variation. Looking at the new motor is apples to oranges unless some very very detailed information comes to light about its bearing clearances and specs through out. With our FA20's FI, NA, SC, Turbo whatever doesn't change the clearances in the bearings and through out the motor.

Even using race cars as a guideline is a horrible idea for a street car. Race cars are much closer maintained and don't have the same life expectancy most consumers need out of there street cars.

The only reason I could see to change oil would you live in a very extreme climate but even then modern oils are much or adaptable then they used to be.

So my opinion is just run a quality 0-20, keep up with the intervals and install an oil cooler.

Mikem53 · 05-20-2014, 10:10 AM

Quote:

Originally Posted by regal

When I switched from 5w30 to ow20 Mazda I found the engine ran better. My only concern is the rod bearings. The crank is the same on the FA20T so 30 weight might not be a bad idea.

Really.. You noticed the engine ran better with a slightly different oil..
How so? That's ridiculous. Anecdotal evidence at its best.

bluesubie · 05-20-2014, 10:59 AM

Quote:

Originally Posted by Mikem53

Really.. You noticed the engine ran better with a slightly different oil..
How so? That's ridiculous. Anecdotal evidence at its best.

Anecdotal evidence, maybe. But it's definitely not ridiculous. The Mazda oil is loaded with molybdenum which has a plating action on engine internals. Anyone that's used a high moly oil (Red Line is another example) will usually report a freer revving and quieter engine. I presume that's what regal means by "better".

Most racing oils have moly in them because it is an excellent friction reducer. More info:
http://www.bobistheoilguy.com/moly-basics/

And a Mazda oil virgin oil analysis:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2897776/1

-Dennis

bluesubie · 05-20-2014, 11:07 AM

Quote:

Originally Posted by Maritime Storm

Don't keep up a great deal with Honda, but I understood that 0W16 was a 2014 model spec. Hadn't been aware that they had reversed decision since December.

I believe they've used it in Japan and/or Europe.

-Dennis

viscositosis.rex · 05-20-2014, 11:16 AM

Finally! People are getting more precise in their numbers. HTHS. Flash Point. UOAs. Do yourself a favor. Go as light as you can get away with. First determine what that is. It's your car. Your driving conditions. Get dialed in. Don't be afraid of the light. Molasses is so old fashioned.

BRZPDX · 05-20-2014, 11:35 AM

I started running 5w30 after going FI. The story is, the turbo has more clearance than the fa20 engine, and the 0w20 was made for mainly emissions and MPG.

Staying N/A, 0w20 should be fine but once going FI, especially a turbo that feeds off the oil from the engine, my shop recommended 5w30 at least, after they had a discussion with Redline. Super Chargers has their own oil feed, so 0w20 should be fine. Dezoris did a UOA after tracking on his Vortech car, and the oil samples came back just fine.

Mikem53 · 05-20-2014, 12:57 PM

Quote:

Originally Posted by bluesubie

Anecdotal evidence, maybe. But it's definitely not ridiculous. The Mazda oil is loaded with molybdenum which has a plating action on engine internals. Anyone that's used a high moly oil (Red Line is another example) will usually report a freer revving and quieter engine. I presume that's what regal means by "better".

Most racing oils have moly in them because it is an excellent friction reducer. More info:
http://www.bobistheoilguy.com/moly-basics/

And a Mazda oil virgin oil analysis:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2897776/1

-Dennis

Sorry.. I'm not buying it.. It's not like other oils today are crap..
Long term affects are one thing.. Feeling those subtle differences if any is another.. I've used redline oil for years in the car I used to track.. For engine protection and sheer strength.. Not because it made the car feel better.. That's just what people want to believe when then spend $$$ for oil..

cdrazic93 · 05-20-2014, 01:44 PM

Quote:

Originally Posted by regal

The Subaru FA20T does have different pistons, they lowered the compression ratio. But the crank is the same so I don't think they would have changed clearances.

At the top of the piston, there is more room with the lower CR than there is with our 12.5:1 CR, which results in tighter spaces for thinner oil to get into, possibly where thicker oil could not. I haven't studied fluid dynamics yet, so I can't give any imperical data.

TouchMyHonda · 05-20-2014, 02:12 PM

Quote:

Originally Posted by cdrazic93

At the top of the piston, there is more room with the lower CR than there is with our 12.5:1 CR, which results in tighter spaces for thinner oil to get into, possibly where thicker oil could not. I haven't studied fluid dynamics yet, so I can't give any imperical data.

How in the world does compression ratio have anything to do with barring and ring clearance?

cdrazic93 · 05-20-2014, 02:37 PM

Quote:

Originally Posted by TouchMyHonda

How in the world does compression ratio have anything to do with barring and ring clearance?

First and second rings are CR rings. The third is the oil ring. The end gaps for rings differ from naturally aspirated to forced induction engines. Since there is more heat in a forced induction engine, the rings have to be treated as a dynamic system rather than a static system. Even in a NA engine. They still heat up and expand, thus the end gaps are different, requiring different oil weights and viscosities.

What we have found is that, even though with the heat from the 12.5:1 CR ontop of the FI, the rings are much more stout than we thought. The clearances are the same for a naturally aspirated engine, which are smaller than the clearances for a turbo engine.

Bearings weren't mentioned in my comment, as I don't know how those are related to CR and ring clearance either.

Sportsguy83 · 05-20-2014, 05:20 PM

Ever since I saw Subaru recommend 5w-30 for FA20DIT, I switched to 5w-30. Of course Im boosted and pushing it hard.

bluesubie · 05-20-2014, 05:47 PM

Quote:

Originally Posted by Sportsguy83

Ever since I saw Subaru recommend 5w-30 for FA20DIT, I switched to 5w-30. Of course Im boosted and pushing it hard.

Did you switch to a 5W-30 that maintains it's viscosity over the interval, or one that shears to a 20 grade?

-Dennis

Sportsguy83 · 05-20-2014, 06:12 PM

Quote:

Originally Posted by bluesubie

Did you switch to a 5W-30 that maintains it's viscosity over the interval, or one that shears to a 20 grade?

-Dennis

From Motul 0w30 xlite to motul 5w30 eco energy I looked at the specs and think it's a little thinner than the 0w30 don't remember

Sent from my SM-N900A using Tapatalk

05-20-2014, 10:10 AM	#16
mrk1 Senior Member Join Date: Mar 2013 Drives: Sterling BRZ Ltd Location: New England Posts: 1,702 Thanks: 403 Thanked 1,389 Times in 671 Posts Mentioned: 21 Post(s) Tagged: 2 Thread(s)	I really don't see a reason to switch from 0-20. Sure its very thin but is thats what is recommended by the people who made the FA20. And I mean the FA20 that is in our cars not another variation. Looking at the new motor is apples to oranges unless some very very detailed information comes to light about its bearing clearances and specs through out. With our FA20's FI, NA, SC, Turbo whatever doesn't change the clearances in the bearings and through out the motor. Even using race cars as a guideline is a horrible idea for a street car. Race cars are much closer maintained and don't have the same life expectancy most consumers need out of there street cars. The only reason I could see to change oil would you live in a very extreme climate but even then modern oils are much or adaptable then they used to be. So my opinion is just run a quality 0-20, keep up with the intervals and install an oil cooler. __________________ The Build Thread GT28RS - eBoost2 - 3.91 Final Drive - Supra LSD

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Quickie: 0w20 vs 5w20 / 5w30	empower-auto	Mechanical Maintenance (Oil, Fluids, Break-In, Servicing)	43	12-17-2016 02:54 PM
Servicing at dealership - do they use 0W20?	Fizz	AUSTRALIA	23	01-13-2015 01:55 AM
Eneos 0w20	Hayashi	Mechanical Maintenance (Oil, Fluids, Break-In, Servicing)	154	10-27-2014 06:04 PM
Redline 0w20, notice to vendors/shops	BRZPDX	Mechanical Maintenance (Oil, Fluids, Break-In, Servicing)	14	05-06-2014 04:26 PM
Anyone want 0.65 liters of Amsoil SS 0W20?	Laika	NY / NJ / CT / PA	0	03-31-2013 07:53 PM

05-20-2014, 11:16 AM	#20
viscositosis.rex Senior Member Join Date: Jun 2013 Drives: Currently 2018 Taco Location: san jose CA Posts: 152 Thanks: 16 Thanked 41 Times in 31 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	Finally! People are getting more precise in their numbers. HTHS. Flash Point. UOAs. Do yourself a favor. Go as light as you can get away with. First determine what that is. It's your car. Your driving conditions. Get dialed in. Don't be afraid of the light. Molasses is so old fashioned.

User Name		Remember Me?
Password