BMW N54 Twin Turbo

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Originally Posted By: WhiteOne
BMW recommends using their 5W-30 oil.
I hear good things about GC 0W-30.
Does this turbocharged engine place special demands on its oil?
Any recommendations on which oil to use...
I'm thinking oil changes every 7500 miles.


Hot and hotter running twin turbos. This looks like an engine tailor-made for RL, although I'm sure the specification approval is lacking.

Otherwise, GC is a good pick here.

Depending on sump capacity and driving habits, I'd run a UOA or two before settling on an optimum OCI. Go short to start, though.
 
Originally Posted By: Craig in Canada
Do a search for "N54", this was heavily discussed, perhaps a year ago. A lot of the info is probably still just as relevant.



Did a search on "N54" across all forums for results newer than 1 year. No hits... Not even this thread. Search is FB.
 
Originally Posted By: Volvohead
This looks like an engine tailor-made for RL

In terms of temperature and mechanical stresses, yes. But remember, there is also fuel dilution. High ester content lubes aren't always the best choice for that (the exception being RLI).
 
Originally Posted By: d00df00d
Originally Posted By: Volvohead
This looks like an engine tailor-made for RL

In terms of temperature and mechanical stresses, yes. But remember, there is also fuel dilution. High ester content lubes aren't always the best choice for that (the exception being RLI).


True. But heat is the bigger stressor here AFAIK. I'd be more concerned if there were plenty of short trips going on, too. Then the POEs can start to have troubles. Otherwise, RL remains my first choice in engines of this type. It has certainly handled our R engine's high heat and mechanical loads.

But you're likely not going to get consistently stellar 15k OCIs with any oil in this engine. The closest for a longer OCI context might be Delvac 1, but he'll be giving up some spool up performance at the heavier weight, and it doesn't carry the spec approval (but can certainly handle it).
 
Heat isn't necessarily the "bigger" stressor; it's just the more popular since it's the most conspicuous -- everyone sees the oil temp gauge and hears the stories about engine shutdowns at the track, whereas almost nobody reads UOAs. From what I've seen, these engines have shown all the signs of serious fuel dilution issues, so it's definitely something to be considered in combination with the heat and mechanical stresses.
 
I probably am more attuned to fuel dilution issues than most; I like to run larger displacement, carburated marine engines on weekends. I doubt this BMW engine causes dilution in that league. Fuel dilution causes viscosity to plummet and can adversely affect lubricity. The typical workaround to that condition is the use of higher viscosity and single viscosity oils. If an engine is self-destructing and people are pointing at fuel dilution of the motor oil as the reason, then the engine has a serious design flaw. I guess BMW should have stuck with the 60 weights if that is going on here. Wouldn't be the first time a 60 fixed BMWs that were flying apart.

But I've never seen dilution cause sludging and eventual starvation the way oxidation from overheating can. And starvation is worse than dilution. Turbos are great at cooking oil (and everything else around them). Our R can heat a 2 1/2 car garage all night after a run. There is no ready solution to oxidation breakdown other than a better base oil or improved additive in some combination.

I probably wouldn't advocate a 5w-30 in this situation. But RL in 10w-30 or 5w-40 should be plenty hardy enough to put up with some dilution. This is also a good situation for an ARX maintenance dose with any oil, although I don't like to mess with the native RL formula.

Turbos are a bit of a tightrope. Go too thick, and spool up goes to pot; too thin, and you can get elevated wear rates in a hurry.

Not saying to ignore the dilution. But between it and heat, I'll address the heat first.
 
Originally Posted By: d00df00d
... everyone sees the oil temp gauge and ...


Unfortunately not in my 535I. No temp gauge.. Just an iDrive / dash warning if things get too hot.

At any rate, these discussions are all well and good, and exceptionally informative. But as the owner of a new 535i with N54 engine under warranty for another 3.5 years, I'm concerned about switching to an oil (like RLI) which may be more ideally suited to the engine, but which does NOT meet the BMW LL approvals. So far, I'm running German Castrol (approved by BMW) and intend to run it no more than 7500 miles between changes. Its my daily driver and I don't plan to track it. So it will not be driven hard. But it will typically get a weekly mix of interstate and local DC area traffic, since my daily work commute requires about 20 miles of interstate driving, 3 or 4 days a week.
 
In the other big thread from earlier this year which is evading the search engine, I recall a couple of points:

- there are oil temperature issues on the cars with no oil cooler. Something like 30*F higher than people would like to see - in the 230-250*F range IIRC Maybe even 260F

- there are huge fuel dilution issues. Testing indicated that most oils (GC, Amsoil AFL, HDEOs included) were "done" in as little as 1000 miles. I certainly wouldn't want to be going 15kmi intervals on BMW 5W30 with my new 335 (if I had one)

- The RLI oil was showing good results, just like in the RS4


On other notes:

Even without a gauge, I'd wager that there's a test mode for the OBC cluster display that will show oil temp, particularly if the engine is equipped with an oil temp shutdown. Ditto for water temp.

I've read that later 335s are fitted with an oil cooler, but have no reference to back that up. "Older" 335 owners may wish to retrofit.

Unfortunately this is all IIRC from the other dozen+ page thread which can't be found
frown.gif
 
Originally Posted By: Craig in Canada
Testing indicated that most oils (GC, Amsoil AFL, HDEOs included) were "done" in as little as 1000 miles.


If that's the case, then this engine has some serious design flaws.
 
Biggest eye opener from that thread, from Terry Dyson:

". . . M1 0w40 which is still one of few M1 products that can perform reasonably well"

After reading that whole thing . . . what a pig of an engine. Looks like another 60 weight TSB. Those little turbos will just love that.
 
Originally Posted By: Volvohead
Originally Posted By: Craig in Canada
Testing indicated that most oils (GC, Amsoil AFL, HDEOs included) were "done" in as little as 1000 miles.


If that's the case, then this engine has some serious design flaws.


I believe some conclusions are that all of the direct injection engines are doing this in North America. The US has mandated something-or-other-pretty-stupid which requires the manufacturers to run their DI engines significantly richer than they'd like to pass USA requirements for a particular kind of emission or something similar. As a result, in various conditions they dump too much fuel and it gets into the oil. I believe Audi, BMW, and Mazda are all affected in the same manner. It's cutting down a little bit of NOx but killing engines, I think. Nice tradeoff.

I believe dilution is far less of a problem in RoW where this particular regulation isn't in place. Maybe they can send the RoW software to Canada too. (I wish - we almost always get lumped in with the US by carmakers)

This seems to have a bit of a Nikasil flavour to it, if you ask me.

It wouldn't surprise me at all of the aftermarket catered to owners by allowing them to correct this USA-specific fuel metering.

Again, IIRC and no references on hand. I'll have to see if I can dig some up - I'm supposed to be on vacation but I can't shake the BITOG habit
grin2.gif
 
Originally Posted By: Volvohead
Originally Posted By: d00df00d
Originally Posted By: Volvohead
This looks like an engine tailor-made for RL

In terms of temperature and mechanical stresses, yes. But remember, there is also fuel dilution. High ester content lubes aren't always the best choice for that (the exception being RLI).


True. But heat is the bigger stressor here AFAIK. I'd be more concerned if there were plenty of short trips going on, too. Then the POEs can start to have troubles. Otherwise, RL remains my first choice in engines of this type. It has certainly handled our R engine's high heat and mechanical loads.

But you're likely not going to get consistently stellar 15k OCIs with any oil in this engine. The closest for a longer OCI context might be Delvac 1, but he'll be giving up some spool up performance at the heavier weight, and it doesn't carry the spec approval (but can certainly handle it).



Can you explain this further: " I'd be more concerned if there were plenty of short trips going on, too. Then the POEs can start to have troubles" (please)
 
Esters are very temperature stable but usually not as chemically stable. Fuel and water can affect them. Short trips mean more fuel dilution and water (condensation) in the crankcase.
 
Originally Posted By: jesbo
Originally Posted By: d00df00d
... everyone sees the oil temp gauge and ...


At any rate, these discussions are all well and good, and exceptionally informative. But as the owner of a new 535i with N54 engine under warranty for another 3.5 years, I'm concerned about switching to an oil (like RLI) which may be more ideally suited to the engine, but which does NOT meet the BMW LL approvals. So far, I'm running German Castrol (approved by BMW) and intend to run it no more than 7500 miles between changes. Its my daily driver and I don't plan to track it. So it will not be driven hard. But it will typically get a weekly mix of interstate and local DC area traffic, since my daily work commute requires about 20 miles of interstate driving, 3 or 4 days a week.


With regards to BMW LL approved oils, BMW NA apparently hasn't received the memo yet. Just for giggles I e-mailed NA from the BMW Owners Circle web site and requested a list of approved oils for my wife's X3 truck. The person who responded stated that Castrol Syntec 5W-30, Mobil 1 5W-30, and Valvoline Synpower 5W-30 were acceptable substitutes for BMW's 5W-30 Synthetic-and not one meets LL-98, never mind LL-01...
 
Originally Posted By: MCompact
... Just for giggles I e-mailed NA from the BMW Owners Circle web site and requested a list of approved oils for my wife's X3 truck. The person who responded stated that Castrol Syntec 5W-30, Mobil 1 5W-30, and Valvoline Synpower 5W-30 were acceptable substitutes for BMW's 5W-30 Synthetic-and not one meets LL-98, never mind LL-01...


I did the same thing right after I took delivery, as I wanted to think ahead about what I would replace the factory fill oil with after 1500 miles of break-in. They responded with basically the same answer and I laughed out loud. After reading this forum and Bimmerfest, I decided I probably couldn't go wrong with GC and in fact it might be a bit better than BMW HP Synthetic. So thats what I used.

The RLI is intriguing, though. I had not heard of it until this thread materialized.
 
Originally Posted By: jesbo

The RLI is intriguing, though. I had not heard of it until this thread materialized.


I believe the RLI in question was actually developed through the work of the RS4 owner from the first thread and Terry Dyson (and RLI, of course).
 
Originally Posted By: Craig in Canada
Originally Posted By: jesbo

The RLI is intriguing, though. I had not heard of it until this thread materialized.


I believe the RLI in question was actually developed through the work of the RS4 owner from the first thread and Terry Dyson (and RLI, of course).


Yes. I read all of that after being referred to that thread. A fascinating thread to say the least.

I currently feel fairly secure in my decision to switch to GC after a 1500 mile break-in on factory fill oil (whatever it is - we don't really know). A number of folks give GC high marks but suggest changing it more frequently than BMW recommends; I always intended to do that.

I am quite concerned about fuel dilution (not even realizing it a few days ago that it was something to be concerned with in DI engines). The last thing I want to have happen is to shorten the life of my N54 in the out years (after warranty) by conforming to BMW's recommended oils during warranty. I tend to keep my cars at least 10 years. If RLI could get LL approvals, problem could be solved.

I think the N54 is an engineering masterpiece; Its one thing that drew me to the 535i in the first place. But I'm beginning to think BMW missed the mark though regarding its real-world lubrication needs.
 
LL approval requires very expensive testing and periodic recertification (I think twice annually, but I could be wrong). I don't see RLI doing it any time soon, unfortunately.

RI_RS4's approach to the warranty issues regarding non-approved oils was his long record of oil analysis data. He figured that if he ever did need to make a warranty claim and Audi denied it on the basis of his choice of oil, he would show a court all the oil analysis data and let it decide the outcome. It sounds like it could be a huge PITA, and of course requires LOTS of UOAs, but it's not entirely implausible. Your call whether you'd like to be that disciplined about it, and whether you're ready to fight in the remote chance you actually have to fight for warranty service.

If you're looking for a fire-and-forget solution that is guaranteed not to annoy BMW, run GC or Mobil 1 0w-40 and change it every 5k miles at most. You should be okay with that.
 
Originally Posted By: d00df00d


If you're looking for a fire-and-forget solution that is guaranteed not to annoy BMW, run GC or Mobil 1 0w-40 and change it every 5k miles at most. You should be okay with that.


Apparently not, at least according to Terry Dyson in the above-mentioned thread. I may have read it wrong, but he seems to think RLI is the only oil that can put up with this engine for more than 1,000 miles.

It's amazing that engines like this are allowed into production (and at such a high price point) with these sorts of issues.
 
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