[Dominus]

Got the good ole lamp +1 so I was gonna pick up some LL01 from a local auto store. I have BMW oil in now. Is it OK to top off with say a European mobile 1?

[deluxe 247]

As long as its the same weight and viscosity and you're just topping off you'll be fine,

[BillionPa]

BMW oil has a Castrol additive pack, if you use Castrol Edge 5W30 or 0W30 you will be best off.

[Dominus]

thank you, so 5w30 or 0w30 should be fine as long as its LL01, best bet would be Castrol or Mobile 1?

oh and here is the oil light for those who come across this thread and dont know what it looks like.

[BillionPa]

Not sure if the 0W30 says LL01, but it is certified by BMWNA for all engines that call for 5W30, including the N54.

How many miles have you gone on the current change?

I would probably need to put over 20000 miles to get a +1 message, since 10K went from a notch over center to center.

[Dominus]

says i have 6000 left. its a 328 so no turbo leaks, and there is no oil residue anywhere that i can see in the bay let alone the ground so i assume it just bunt it up. ive driven about 100 miles with the light .... i will def pick up some kind of 5w30 just to be safe. advanced auto is the best choice within 30 miles of me so ill prob just get whatever they have
thanks for the help

[Dominus]

So they only carry edge spt 5w40 is this ok?

[ihsanshaik]

You know the dealer tops off for free....

[Dominus]

dealers over 40 min away and im not under warranty. and with 60 hour work weeks i would just rather grab this stuff from advanced and be done with it

[ihsanshaik]

No I understand. Out of warranty or not they will do it.

[BillionPa]

the 5W40 will be fine for 1qt top off, but it has more VII in the oil.

Castrol Edge 5W30 (old edge not new edge) and 5W40 both meet LL01
BMW oil is Castrol SLX Longtec LL01

The rule of oil is use the thinnest possible oil providing the highest HTHS protection at a given grade, with the lowest evap loss, and the least amount of VIIs. Our engines require ACEA A3/B3 or ACEA A3/B4 (N54) spec oil, so finding the thinnest oils that will do that job is the general rule of thumb (30wt)

There are other oils available that either have lower pour points/higher viscosity index, or lower evap losses, or higher HTHS, these include:

Castrol Syntec 0W30 (lower evap, lower pour point, no VIIs, LL01)
M1 0W40 (lower evap, lower pour point, HTHS 3.7, LL01)
Redline 5W30 (lowest evap, HTHS 3.8, no VIIs)

Even though the M1 0W40 and Castrol 0W30 are actually the same thickness when warm, even though their listed grades say otherwise, close to what would be considered a 0W35 grade.

All of those oils are fine either as topoff or for oil change, and all have their own benefits for specific driving styles and environments, and are superior to BMW oil.

[NoTempoLimitN54]

Originally Posted by BillionPa

...The rule of oil is use the thinnest possible oil providing the highest HTHS protection at a given grade, with the lowest evap loss, and the least amount of VIIs. Our engines require ACEA A3/B3 or ACEA A3/B4 (N54) spec oil, so finding the thinnest oils that will do that job is the general rule of thumb (30wt)...

What's the basis for going with the thinnest oil? I have an N54 so my oil temps get up to 245º F every day (I have stock oil cooler). I have my doubts about xW-30 oils in the N54 (with the exception of German Castrol 0W-30 which is a heavy 30 wt).

Right now I'm doing a "cleaning phase" of 4k OCI's to make up for the 12-15k OCI's my N54 had before I bought my car (at 43k). I'm running Shell Rotella T6 5W-40 right now (coming out this weekend). Then switching to Castrol 5W-40 LL01, then 4k later a dealer oil change with the BMW oil. At that point any sludge from the lengthy CBS OCI's should be flushed out.

I've put 4100 miles on this oil and the oil level has only gone down to the 3/4 mark. On the BMW 5W-30 I would have easily burned a quart by now.

Considering the cost of walnut shell blasting to get the oil residue and carbon off the intake valves, I think there is definitely a motivation for N54 owners to go with a heavier oil with less evaporation.

[BillionPa]

thinner oil flows better, simple physics, viscosity = resistance to flow

also, heavier oil does NOT equal less evaporation, Redline 0W20 has less evaporation than Rotella T6 5W40 (which is about the same as Castrol 0W30)

remember, it is not just choosing the thinnest oil, but the one that provides the best protection to the engine under the expected operating conditions, and best protection is defined not just by technical characteristics, but by actual performance in the engine

if more protection is required (racing, extended high temp/low oil pressure) then a different viscosity may be required, but generally BMW engines and their oil systems are designed for weights between 30 and 40, and exceeding that will create a reduction in oil flow