[bobkat09]

I’m not looking to fire up another debate about oil but Im getting ready to do my first 5k oil change on my M240

My concern is that the recommended 0w20 is too thin. I have owned many BMWs over the last 20 years and have always used Castrol 0w40 oil with no problems. I live in a hot weather climate and I don’t think that a thin oil will stand up.

I’m thinking that BMW recommends this oil for increased fuel efficiency. But I’m not willing to have premature engine wear to achieve a 0.1 mpg increase.

[cristo]

I changed our M240i to BMW
TwinPower Turbo 0w30 (gas
version of course) at about
1200 miles because of my
concern over the recommended
factory fill 0w20.
Still warranty friendly since
0w30 is listed as an acceptable
alternative weight.

[RvR]

Originally Posted by bobkat09

I’m not looking to fire up another debate about oil but Im getting ready to do my first 5k oil change on my M240

My concern is that the recommended 0w20 is too thin. I have owned many BMWs over the last 20 years and have always used Castrol 0w40 oil with no problems. I live in a hot weather climate and I don’t think that a thin oil will stand up.

I’m thinking that BMW recommends this oil for increased fuel efficiency. But I’m not willing to have premature engine wear to achieve a 0.1 mpg increase.

Though as AFAIK, more wear takes place a cold start rather than high temperatures, and higher viscosity isn't a help at cold start.

The other consideration, IIRC, the B58 has always been spec'd with 0W-20, so the size of the oil passages and pressures should have all that taken into account. (Now in an S54, for example, then you want a much higher top viscosity, but that's a 20 year-old unrelated design to your B58.)

In reading up on the various BMW OE oils (which are made by Shell/Pennzoil), it looked to me that FE17+ was better than the FE14+ in that the 17 had lower residual ash (i.e., better for DFI motors.) Something like this:

https://www.getbmwparts.com/p-b58-en...and-on-pkb58oc

So yes, I understand your concern about the oil being too thin, but what's the evidence that the 20 is "too" thin?

If it were me, I'd use a FE17+ change kit, and send in a sample of your used oil to see what a lab says. Then you'll know what was going on, and you can ask the lab questions about how well the original oil fared.

HTH.

[BimBimM2]

Originally Posted by bobkat09

I’m not looking to fire up another debate about oil but Im getting ready to do my first 5k oil change on my M240

My concern is that the recommended 0w20 is too thin. I have owned many BMWs over the last 20 years and have always used Castrol 0w40 oil with no problems. I live in a hot weather climate and I don’t think that a thin oil will stand up.

I’m thinking that BMW recommends this oil for increased fuel efficiency. But I’m not willing to have premature engine wear to achieve a 0.1 mpg increase.

If you look into my post history, you'd notice that I have started similar threads here and on Reddit.

The conclusion I reached is simple: as long as I am under warranty I will let BMW stick to their recommendations and let the dealerships do the oil changes. I follow the 5000 mile change schedule and changed it at 1200 as well. However after going through BobTheOilGuy forums I am fine with 0w20. People say that shitty CAFE standards are the reason BMW shifted to the water like 0w20 but, really, they aren't in the business of being called unreliable. Trust their engineers and the tolerances they build in the engine, and the tolerances they account for, instead of letting your own intuition guide you.

[dradernh]

Originally Posted by bobkat09

My concern is that the recommended 0w20 is too thin. I have owned many BMWs over the last 20 years and have always used Castrol 0w40 oil with no problems. I live in a hot weather climate and I don’t think that a thin oil will stand up.

I’m thinking that BMW recommends this oil for increased fuel efficiency. But I’m not willing to have premature engine wear to achieve a 0.1 mpg increase.

Makes sense, and I suspect quite a few owners in hot weather climates are running higher viscosity oils. Below is some info specific to our engines that I've collected on the subject.

From my 2017 Owner's Manual


BMW's current recommendations: https://www.newtis.info/tisv2/a/en/f...enance/1PSryV8 and
https://www.newtis.info/tisv2/a/en/f...nce/1VncAYo9NI

A note from FCP Euro on this page: https://www.fcpeuro.com/products/bmw...11428583898-lm

"New BMW's fitted with BXX series engines "Require" 0W-20 LL14FE+ Rated oils. WE DO NOT RECOMMEND using this spec! The levels of protection LL14FE provides are much lower than LL01. The new formulation LL14FE is mainly designed with CAFE ratings, EPA requirements and fuel mileage in mind, NOT OVERALL PROTECTION."

[FCBuff]

Ow-40 isn't going to hurt it. Use it if it makes you sleep better. I have been using it for years in n55's, both Castrol and mobil 1 varieties.

You are correct, it is all about MPG. I like the switch to the BMW 0w-30, it is designed for our more modern turbo charged engines. Keeps the approval rating etc. Seems like an ideal compromise to me.

You will get all kinds of answers to this, so will have to cut thru the smoke and do what makes sense to you. Your car won't blow up with any of the choices.

[aerobod]

Although the manual says that other grades of synthetic can be used besides 0w20 and 0w30, that is only for a maximum of 1 litre when the oil level is low.

Using a 0w40 oil will likely not cause a problem, but engineering wise the engine was designed for 0w20, so 0w40 when hot will have lower flow rates and hence less cooling of areas with tight tolerances than the thinner 0w20. Bearing areas and oil passages are also sized for the thinner oil, so there is unlikely to be any risk of metal-to-metal contact.

Also bear in mind that standard ATF fluid has a lower viscocity than 0w20 oil and in vehicles under high towing stress will reach temperatures equivalent to engine oil under hard use. The contact point between gear teeth is a smaller area than in the big and small ends in the engine with the oil under much higher pressure between the teeth and no issues with wear.

[morphomeman]

I will never cease to be amazed by folks who think that the manufacturer, particularly BMW, got it wrong, especially when it comes to motor oil. The name of the company is Bavarian Motor Works. They have depended on their reputation for building great engines for almost a century. Why on earth would a single individual, presumably one who does not design internal combustion engines for a living, decide to second guess BMW's recommendation for the viscosity of the oil in their engine?
And then there is the conspiracy/compromise aspect of the argument: they design the engine to run 50,000 miles, because after that it is the owner's problem. Being totally unprovable, it is exactly the sort of thing that conspiracists love.
If anyone needs any hydroxychloroquine, I will sell it to you at the right price, along with a large supply of masks that I don't need any more.

[BimBimM2]

Originally Posted by morphomeman

I will never cease to be amazed by folks who think that the manufacturer, particularly BMW, got it wrong, especially when it comes to motor oil. The name of the company is Bavarian Motor Works. They have depended on their reputation for building great engines for almost a century. Why on earth would a single individual, presumably one who does not design internal combustion engines for a living, decide to second guess BMW's recommendation for the viscosity of the oil in their engine?
And then there is the conspiracy/compromise aspect of the argument: they design the engine to run 50,000 miles, because after that it is the owner's problem. Being totally unprovable, it is exactly the sort of thing that conspiracists love.
If anyone needs any hydroxychloroquine, I will sell it to you at the right price, along with a large supply of masks that I don't need any more.

Planned obsolescence is a thing. I promise you that.

[Dylan86]

I personally wouldn't put 0w20, 5w20, 0w30 in these cars. Thinnest should be 0w40, next to 5w30. BMW did revise these at some point to 0w30, but I'm not running winter temps so I stick with what came with the car. 5w30 LM and no concerns.

[TajoMan]

I run BMW 0w20 in winter and castrol 0w40 in summer.
As an engineer, I should trust their spec but I know sometimes (or many times) engineers pushed by upper management to prioritize wrong things.

I am wondering what S58 engine uses.

[bobkat09]

I’ve done a little research and found that the US is the only country that 0w20 oil is recommended. All other countries run regular viscosities. Seems to be driven by CAFE standards and fuel efficiency

Comes down to engine protection vs fuel efficiency

[morphomeman]

Intriguing that only US requires this viscosity.
Do all other markets have a single recommendation or does it vary further?
Just curious.

[chattanooga240]

Originally Posted by bobkat09

I’m not looking to fire up another debate about oil but Im getting ready to do my first 5k oil change on my M240

My concern is that the recommended 0w20 is too thin. I have owned many BMWs over the last 20 years and have always used Castrol 0w40 oil with no problems. I live in a hot weather climate and I don’t think that a thin oil will stand up.

I’m thinking that BMW recommends this oil for increased fuel efficiency. But I’m not willing to have premature engine wear to achieve a 0.1 mpg increase.

You bought a brand new car, follow the manufacturer and let it be.

[bobkat09]

Originally Posted by morphomeman

Intriguing that only US requires this viscosity.
Do all other markets have a single recommendation or does it vary further?
Just curious.

As far as I can tell only the US models have the lighter weight oil recommendations.

[dradernh]

Originally Posted by bobkat09

I’ve done a little research and...All other countries run regular viscosities.

What are those viscosities - inquiring minds would very much like to know.

[aerobod]

Standard UK, Canada and EU market oil for the B58 engine available from BMW dealers is 0w30 Twin Power Turbo Gold LL-12FE, but the owner's manual lists 0w30 LL-12FE or 0w20 LL-14FE as the correct oil for a complete fill. LL-01 rated synthetics in 0w30, 5w30, 0w40 and 5w40 are stated as suitable for up to 1 litre top-up between oil changes.

[BimBimM2]

Originally Posted by aerobod

Standard UK, Canada and EU market oil for the B58 engine available from BMW dealers is 0w30 Twin Power Turbo Gold LL-12FE, but the owner's manual lists 0w30 LL-12FE or 0w20 LL-14FE as the correct oil for a complete fill. LL-01 rated synthetics in 0w30, 5w30, 0w40 and 5w40 are stated as suitable for up to 1 litre top-up between oil changes.

Aerobod, just wanted to thank you for having well thought out and helpful responses in this thread! Cheers!

[Winemaker2]

Just brought my car in for its last oil change included in the initial maintenance program. The SA recommended 0W20 especially since I only have 15.5K on the car. He said moving up to 0W30 in Northern CA wouldn't make much of a difference. Until the car gets 40K on it or you move to a desert, 0W20 should be just fine. If it became a track car, then that's an entirely different discussion. Seems to be consistent with what we have been saying on this thread.