Oil viscosity questions for H6 EZ30d phase 1. Anyone have direct experience with Liqui Moly oil?

[laegion]

I've been using the subaru synthetic 5w30, a mechanic friend of mine recommended Liqui Moly and that I might try their 5w40. I seem to remember very specific recommendations about only using 5w30; but I can't find mention of it when searching. I'm wondering why a specific viscosity would be recommended for this engine? Also any recommendations on high quality synthetic that works well with this motor are appreciated. I'm hoping to find something available in local parts stores if possible. but at least something I don't have to order form a dealership as we don't have one in my town. If it's also better than the factory subaru oil that would be a bonus.

Edited March 12, 2022 by laegion

[forester2002s]

I suspect that the manufacturer's recommendations for oil viscosity have more to do with meeting fuel consumption limits, than other reasons.

[lmdew]

Amsoil ships free over $100.  Get 2 oil changes and filters and you are set for 2 years.

[heartless]

my other half has a 2006 LL Bean Outback with the H6 and just uses a readily available brand of the recommended type - he has had the car for about 8 yrs now, and no issues, so i dont think brand is all that important, tbh.
obviously, dont by the cheapest crap out there, but it isn't necessary to buy the most expensive, either.

 

[laegion]

I appreciate the general info.

I'm really looking for specific info about the ez30d phase I. The reason is that I recall GD mentioning something about this in another post but I can't find it and I don't think he explained the reason for the specific viscosity.

I've read a lot about Subarus and watched hundreds of hours of videos, etc. The viscosity choice is by and large about fuel consumption from what I understand. However there are always exceptions to any rule.

Also, an '06 would have a phase II EZ motor so I'm not sure it would be the same, since it has VVT, a redesigned front cover and timing chain system from what I understand.

Sadly, two oil changes would only last me 3 months right now as I'm driving this car for work until I get my '95 back up and running. I've heard good things about amsoil...but I'm inclined to listen to my mechanic friend when it comes to fluid recommendations. Unfortunately he's not a Subaru specific tech so he's unfamiliar with any reason the ez30d might need a specific viscosity.

It's also possible I'm remembering it wrong; but I'd hoped one of the subaru techs on the board would know about this if it's common knowledge in the field.

[idosubaru]

On 3/10/2022 at 12:15 AM, laegion said:

I appreciate the general info.

I'm really looking for specific info about the ez30d phase I. The reason is that I recall GD mentioning something about this in another post but I can't find it and I don't think he explained the reason for the specific viscosity.

I've read a lot about Subarus and watched hundreds of hours of videos, etc. The viscosity choice is by and large about fuel consumption from what I understand. However there are always exceptions to any rule.

Also, an '06 would have a phase II EZ motor so I'm not sure it would be the same, since it has VVT, a redesigned front cover and timing chain system from what I understand.

Sadly, two oil changes would only last me 3 months right now as I'm driving this car for work until I get my '95 back up and running. I've heard good things about amsoil...but I'm inclined to listen to my mechanic friend when it comes to fluid recommendations. Unfortunately he's not a Subaru specific tech so he's unfamiliar with any reason the ez30d might need a specific viscosity.

It's also possible I'm remembering it wrong; but I'd hoped one of the subaru techs on the board would know about this if it's common knowledge in the field.

Owners manual is a good source for viscosity.  When searching here - search his user name and "Amsoil", his most detailed responses involve that.  Google search might work better but it should be readily available here too. And you might try searching his posts for EZ30 in case he's ever pointed it out.

Oil opinions are 99% of the time not given by someone acutely aware of failure modes, causes, metallurgical deterioration, interplay of lubricity degradation and heat escalation, oil degradation, or any kind of engineering/large scale data analysis, when it comes to oil induced issues. This isn't a big deal except when we consider how obsessed people are with oil choices.  Except maybe GD. Hours and hours of internet reading/watching is just a bunch of half-baked (at best) opinions and picking whatever sounds good, there's nothing scientific, engineering related, or data driven about that.

But here's the thing - it doesn't matter.  Run synthetic, never let it get low, and change it on time and you'll never have an oil induced issue. Outside of "don't be dumb", follow the owner manual, there's no chance of viscosity giving any meaningful benefit (ignoring fuel mileage) for an average daily driver.  Change two different EZ30's from new with 5w30 and 10w30 for 200k and if it's never run low or past interval there will be no difference.

EZ-30 guts/materials/clearances are commensurate with all modern subaru engines.  There's nothing special regarding the EZ30 related to oil viscosity.  There's not much information or consensus because it doesn't matter. That engine runs 250,000 miles all day long on the cheapest on sale oil you can find if it never gets low, and is changed frequently.  Technically even conventional oil is fine if you change it a lot, but synth is so good and forgiving of potential running hot, or low oil, or other compromising events, and longer change intervals, it's silly not to run it. 

There are two minor oil related considerations on the EZ:
1. the timing chain tensioner supplies

2. the EZ30 has 6 cylinders - so failure or incidence rates of unforgiving circumstances will be 50% higher when speaking about the combustion chamber just mathematically speaking.

Keeping the oil clean, full, and changed regularly is key to those two points far more than viscosity...again, follow the owners manual. 

[laegion]

15 hours ago, idosubaru said:

Owners manual is a good source for viscosity.  When searching here - search his user name and "Amsoil", his most detailed responses involve that.  Google search might work better but it should be readily available here too. And you might try searching his posts for EZ30 in case he's ever pointed it out.

Oil opinions are 99% of the time not given by someone acutely aware of failure modes, causes, metallurgical deterioration, interplay of lubricity degradation and heat escalation, oil degradation, or any kind of engineering/large scale data analysis, when it comes to oil induced issues. This isn't a big deal except when we consider how obsessed people are with oil choices.  Except maybe GD. Hours and hours of internet reading/watching is just a bunch of half-baked (at best) opinions and picking whatever sounds good, there's nothing scientific, engineering related, or data driven about that.

But here's the thing - it doesn't matter.  Run synthetic, never let it get low, and change it on time and you'll never have an oil induced issue. Outside of "don't be dumb", follow the owner manual, there's no chance of viscosity giving any meaningful benefit (ignoring fuel mileage) for an average daily driver.  Change two different EZ30's from new with 5w30 and 10w30 for 200k and if it's never run low or past interval there will be no difference.

EZ-30 guts/materials/clearances are commensurate with all modern subaru engines.  There's nothing special regarding the EZ30 related to oil viscosity.  There's not much information or consensus because it doesn't matter. That engine runs 250,000 miles all day long on the cheapest on sale oil you can find if it never gets low, and is changed frequently.  Technically even conventional oil is fine if you change it a lot, but synth is so good and forgiving of potential running hot, or low oil, or other compromising events, and longer change intervals, it's silly not to run it. 

There are two minor oil related considerations on the EZ:
1. the timing chain tensioner supplies

2. the EZ30 has 6 cylinders - so failure or incidence rates of unforgiving circumstances will be 50% higher when speaking about the combustion chamber just mathematically speaking.

Keeping the oil clean, full, and changed regularly is key to those two points far more than viscosity...again, follow the owners manual. 

I agree, that's why I typically only take advice from ASE certified techs when it comes to this sort of thing, which is why I listen to my friends advice on oil, he's been an ASE certified diagnostic pro for over a decade; but he's not a subaru tech specifically so his knowledge in this area isn't as thorough as the techs prowling this board. It's why I'm here and not on some FB group where every "know it all" gives a useless opinion.

I only run synthetic in both of my Subies, and have for years. I can get amsoil, and certain formulations of the Liqui Moly locally. I'm mostly only interested in the liqui moly because my friend says he's had really good results with it in several vehicles. Better than some of the more expensive brands as it's formulated for high end European engines, (not the lowest bidder an OEM could contract). I'm skeptical of course so that's why I'm asking about direct experience with Liqui Moly or different viscosities in the ez30.

I know all the differences between synthetic and organic oil. I know in the majority of engines viscosity isn't as important as it's made out to be. I've actually owned over 30 cars in the 20 years I've been driving and worked on almost all of them. I've already done an engine swap on both my Subies...so I'm not a newbie; I know the basics.

I'm really only posting about this because I am curious about the effect of viscosity on the timing chain tensioners of the EZ30D Phase I specifically.

I've tried multiple searches using the forum search feature with no luck. I'll try using Google as you suggest.

Thanks for the info.

[GeneralDisorder]

In my personal opinion, ASE papers don't mean squat. In over a decade of being the face of my business - the guy you see at the counter and the guy that answers the phone - I have been asked a grand total of THREE times if I have ASE certifications, etc. In each case I explained what that really means and the customer brought me their car anyway. It's a waste of time and effort - much like college. I can get the same or better education for $12 in late fees at the public library and as regards "auto mechanics" - which isn't really a term I like - I prefer "machinist" - as in someone that is involved in building, understanding, and repairing machines in general - I don't really limit myself to automotive......

Oil viscosity and additive package is chosen by the manufacturer based on emissions, fuel economy, emissions, bearing loads, emissions, longevity, emissions, maintenance cost and interval, emissions...... oh and did I mention emissions? 

If you want the best protection then you really only need to consider the load on the engine. Higher viscosity resists being squeezed out of the bearings. That's why the higher power engines (turbo and H6) specified 5w30 rather than the 5w20 used in the newer NA engines. The construction of the engine internally - oil pump sizing, bearing clearances, etc - is no different between engines that "recommend" different viscosities. In general the manufacturer chooses the thinnest oil they can "get away with" that has the lowest additive package they can "get away with" and thus have the lowest emissions and least damage to emissions equipment (which has a federally mandated extended warranty). If you look at many of the high powered factory cars.... BMW for example ran 10w60 on many of their high powered turbo engines from the factory. 

We use exclusively 5w40 and higher viscosity in all our oil changes unless there is specific concern about voiding a warranty, etc. Anything above about 400 HP we use 5w50. I have been using this policy on EVERY car we service - probably about 1000 oil changes a year - for about 8 years at this point. We are an Amsoil dealer and our go-to oil is the 5w40 Euro Full SAPS formula (black lid). The high power cars get the 5w50 Signature Series. We use WIX filters. We set all the oil change intervals for 6,000 miles and we always remind people to check their oil level regularly.

I have lots of customers making 500+ WHP on Amsoil and I have torn down a LOT of engines - I have never seen a single failure of one of our engine builds that could be logically linked to a failure of the oil to prevent metal-to-metal contact. 

And for that matter - 99.999% of every engine failure I have seen has been related to the engine running low on oil, or being starved of oil. The type of oil matters very little when it's littered with debris from bearings that are starved of oil every time you take a hard corner (low oil level) and from people starting and driving with the engine cold and the bearing clearances half what they are at operating temp and the oil filter in bypass just shoving all that oil and debris through the bearings like a lapping compound. 

You want the engine to last? Run a high quality synthetic and a filter with an up-front bypass design. Don't drive it hard when it's cold - you'll just put the filter in bypass and main bearing clearances are tight when cold. Keep it topped off. Change it on a regular schedule. 

The Brand of the oil is pretty much irrelevant. Amsoil, Redline, Royal Purple, Lubri-Moly, Motul, etc..... it's pretty much all just marketing. They will all do the same job if you keep it full and clean. Do this and the engine will live plenty long enough to leak from everywhere and lose the HG's and end up being junk since it's cheaper to just get a JDM replacement. Timing components aren't a concern and none of them can read the label on the bottle of oil you pour in. 

GD

Edited March 12, 2022 by GeneralDisorder

[laegion]

11 hours ago, GeneralDisorder said:

In my personal opinion, ASE papers don't mean squat. In over a decade of being the face of my business - the guy you see at the counter and the guy that answers the phone - I have been asked a grand total of THREE times if I have ASE certifications, etc. In each case I explained what that really means and the customer brought me their car anyway. It's a waste of time and effort - much like college. I can get the same or better education for $12 in late fees at the public library and as regards "auto mechanics" - which isn't really a term I like - I prefer "machinist" - as in someone that is involved in building, understanding, and repairing machines in general - I don't really limit myself to automotive......

Oil viscosity and additive package is chosen by the manufacturer based on emissions, fuel economy, emissions, bearing loads, emissions, longevity, emissions, maintenance cost and interval, emissions...... oh and did I mention emissions? 

If you want the best protection then you really only need to consider the load on the engine. Higher viscosity resists being squeezed out of the bearings. That's why the higher power engines (turbo and H6) specified 5w30 rather than the 5w20 used in the newer NA engines. The construction of the engine internally - oil pump sizing, bearing clearances, etc - is no different between engines that "recommend" different viscosities. In general the manufacturer chooses the thinnest oil they can "get away with" that has the lowest additive package they can "get away with" and thus have the lowest emissions and least damage to emissions equipment (which has a federally mandated extended warranty). If you look at many of the high powered factory cars.... BMW for example ran 10w60 on many of their high powered turbo engines from the factory. 

We use exclusively 5w40 and higher viscosity in all our oil changes unless there is specific concern about voiding a warranty, etc. Anything above about 400 HP we use 5w50. I have been using this policy on EVERY car we service - probably about 1000 oil changes a year - for about 8 years at this point. We are an Amsoil dealer and our go-to oil is the 5w40 Euro Full SAPS formula (black lid). The high power cars get the 5w50 Signature Series. We use WIX filters. We set all the oil change intervals for 6,000 miles and we always remind people to check their oil level regularly.

I have lots of customers making 500+ WHP on Amsoil and I have torn down a LOT of engines - I have never seen a single failure of one of our engine builds that could be logically linked to a failure of the oil to prevent metal-to-metal contact. 

And for that matter - 99.999% of every engine failure I have seen has been related to the engine running low on oil, or being starved of oil. The type of oil matters very little when it's littered with debris from bearings that are starved of oil every time you take a hard corner (low oil level) and from people starting and driving with the engine cold and the bearing clearances half what they are at operating temp and the oil filter in bypass just shoving all that oil and debris through the bearings like a lapping compound. 

You want the engine to last? Run a high quality synthetic and a filter with an up-front bypass design. Don't drive it hard when it's cold - you'll just put the filter in bypass and main bearing clearances are tight when cold. Keep it topped off. Change it on a regular schedule. 

The Brand of the oil is pretty much irrelevant. Amsoil, Redline, Royal Purple, Lubri-Moly, Motul, etc..... it's pretty much all just marketing. They will all do the same job if you keep it full and clean. Do this and the engine will live plenty long enough to leak from everywhere and lose the HG's and end up being junk since it's cheaper to just get a JDM replacement. Timing components aren't a concern and none of them can read the label on the bottle of oil you pour in. 

GD

Well then, 5w40 it will be. I was using the subaru synthetic and the subaru filters but I've heard the filters they sell in the American market are not very good so back to Napa Gold/wix.

I should say, I don't trust my friend because he's ASE certified. I trust him because we started working on cars together doing engine swaps on 80's Camaro's, and aircooled VW's etc over 20 years ago and now he's one of the best diagnostic techs around.

 

I like your philosophy about being a "machinist" rather than a mechanic...it makes perfect sense. I've worked on a lot of machines: like a huge pitney bowes sorter/inserter, and RC cars and designed/built FPV quads and the skills are all related. My friend is the same way.

 

I appreciate the detailed info. I just didn't want to go from the OEM on this motor without more info since it's a low mikeage JDM motor Injust spent a bundle installing, and it's different than what I'm used to. I haven't had a motor with chain driven cams probably since I sold my 76 Datsun 620.

and yes...driving cold vehicles is one thing that irritates the hell out of me. I'm sure everyone I know is sick of me telling them it's bad for their car. I'm the kind of driver if I have to drive it cold I basically coast it with minimal load till it's warm. No need to destroy my bearings or break piston skirts.

Is there a specific filter from wix you'd recommend for the EZ30D specifically or just the same as the EJ series? That's what napa sold me when I went to get a filter for this thing.

 

Thanks again; this info puts my mind at ease.

[somick]

I love  the attitude of @GENERAL DISORDER II - that is the way to be when you believe in what you are doing but my Camry, Accord and Loyale ALL easily reached 200, 000 miles with the cheapest oils I could buy, the factory specified viscosities  and 5,000 miles oil change intervals.  The only rule I have - I avoid Fram filters at any cost.  My Forester is at 122,000.

 

I may be lucky...

 

Sam

[88SubGL]

I have an ‘85 Nissan pickup that had 400,000 miles on it before I opened it up after it blew a head gasket. I bought it with 75,000 miles on it and used whatever was the cheapest oil and filter I could find, including Fram filters, and changed the oil every 3,000 miles. I was surprised to find the factory crosshatching in the cylinders. Cleaned up the pistons, re-ringed it, new bearings, timing set and head reworked and it runs as good as when I first bought it. Point being, based on my personal experience, it’s much less about brands than frequency.

 I also have an ‘04 Frontier with 281,000, an ‘04 Tahoe with 212,000 and a ‘15 Legacy with 148,000. All running strong.

[idosubaru]

On 3/12/2022 at 12:30 AM, laegion said:

I agree, that's why I typically only take advice from ASE certified techs when it comes to this sort of thing, which is why I listen to my friends advice on oil, he's been an ASE certified diagnostic pro for over a decade; but he's not a subaru tech specifically so his knowledge in this area isn't as thorough as the techs prowling this board. It's why I'm here and not on some FB group where every "know it all" gives a useless opinion.

I only run synthetic in both of my Subies, and have for years. I can get amsoil, and certain formulations of the Liqui Moly locally. I'm mostly only interested in the liqui moly because my friend says he's had really good results with it in several vehicles. Better than some of the more expensive brands as it's formulated for high end European engines, (not the lowest bidder an OEM could contract). I'm skeptical of course so that's why I'm asking about direct experience with Liqui Moly or different viscosities in the ez30.

I know all the differences between synthetic and organic oil. I know in the majority of engines viscosity isn't as important as it's made out to be. I've actually owned over 30 cars in the 20 years I've been driving and worked on almost all of them. I've already done an engine swap on both my Subies...so I'm not a newbie; I know the basics.

I'm really only posting about this because I am curious about the effect of viscosity on the timing chain tensioners of the EZ30D Phase I specifically.

I've tried multiple searches using the forum search feature with no luck. I'll try using Google as you suggest.

Thanks for the info.

 

Another question which is a better fit is: "Are there any oil induced failures or issues that oil choice could mitigate?"  There are none. Most oil decisions/questions try to solve an issue that doesn't exist.  With a 20 year old model, there's many thousands of examples with a total of billions of miles of opportunity for the greater Subaru community to see any issues, timing tensioner, or otherwise.  The good news in all this - is it truly doesn't matter at all.  So you'll be right whatever you choose.  Enjoy the JDM i've installed JDM EZ30's as well. 

 

[laegion]

6 hours ago, idosubaru said:

 

Another question which is a better fit is: "Are there any oil induced failures or issues that oil choice could mitigate?"  There are none. Most oil decisions/questions try to solve an issue that doesn't exist.  With a 20 year old model, there's many thousands of examples with a total of billions of miles of opportunity for the greater Subaru community to see any issues, timing tensioner, or otherwise.  The good news in all this - is it truly doesn't matter at all.  So you'll be right whatever you choose.  Enjoy the JDM i've installed JDM EZ30's as well. 

 

I hope to enjoy it for quite a few years. It's a very nice engine. I love my EJ22...but 6cyl just have such smooth power delivery and this one has such a flat torque curve. It's going to be a great roadtrip and light overlanding vehicle.

[idosubaru]

9 hours ago, laegion said:

I hope to enjoy it for quite a few years. It's a very nice engine. I love my EJ22...but 6cyl just have such smooth power delivery and this one has such a flat torque curve. It's going to be a great roadtrip and light overlanding vehicle.

Those H6's are the most recommended Subaru I've helped a lot of people buy/repair, many first time Subaru owners I know I helped them into an H6.. since all the Ej22's rusted out many years ago around here. 

[1 Lucky Texan]

a very long time ago, I recall hearing of a test done with NYC taxicabs. They actually tore down some engines and measured wear. They let some go without oil or filter changes for a very long time. Just topped-off. (sry, don't recall specifics) - pretty much, if thye had oil in them they were fine. (not really an apples to apples comparison I guess as they idle a lot and are parked indoors.....still....?)

 

I have run 5w-40 primarily because, a car can sit around in a parking lot for 8 hours in august here. Underhood temps can get quite high. I just felt that I didn't want some thin oil running out of the bearing surfaces . 'They' say there is significant wear at the moment of starting a car because you have zero oil pressure for an instant.