BMW 5-30 vs. M1 0-40

[antonmnster]

My semi-annual OC is coming up and I can't for the life of me decide whether I should use the OEM 5-30 oil or 0-40 M1. The BMW oil is about $.5/qt cheaper than the M1, and a dealership is closer to my house than WM.

Sounds like the M1 is a better oil but I also keep noticing that the Fe in UOAs is higher than I'd like to see, and every engine I've run M1 sounds clackity (a scientific term, I know).

The BMW oil seems quieter, seems more shear-stable, but already has a history of leaving a fair amount of sludge in my engine.

Anyone else in this tough conundrum?

 

[addyguy]

Both are good oils, can't really go wrong with either.

HOWEVER, I would say that of all the M1 grades, the 'FE' problem will probably NOT show up with the 0W-40 grade - it is a very, very good oil.

 

[JHZR2]

I wouldnt sweat it either way unless your weather would provide benefit from a 0w- oil.

 

[d00df00d]

Originally Posted By: antonmnster
My semi-annual OC is coming up and I can't for the life of me decide whether I should use the OEM 5-30 oil or 0-40 M1. The BMW oil is about $.5/qt cheaper than the M1, and a dealership is closer to my house than WM.

I'd pick the BMW oil on this basis alone, honestly.


However, for the sake of discussion:
Originally Posted By: antonmnster
Sounds like the M1 is a better oil but I also keep noticing that the Fe in UOAs is higher than I'd like.

This has been addressed countless times and is really a non-issue. If these Fe numbers were coming from wear per se, Mobil 1 would consistently show higher numbers for other metals too, which it does not. It's probably an odd chemical quirk of the oil.


Originally Posted By: antonmnster
The BMW oil seems quieter, seems more shear-stable, but already has a history of leaving a fair amount of sludge in my engine.

How often do you change it? What's your oil consumption like? Is your PCV system in good order?

If you really are getting sludge, your choice of oil probably won't help much.

 

[antonmnster]

The sludge is from the first owner who followed the OBC OCIs for the first 135,000 miles or so. It's really just a little bit of stuff on the VANOs, but I'm used to my e36, which was completely spotless at 250,000 (thanks Delo 15-40). I'm just not used to seeing anything under the VC.

I've been changing the oil about at about 3-4k. I know it could be more, but my work is only 1.4 miles away, and all those short trips generate major condensation in the winter.

PCV hasn't presented itself as an issue - yet. The elbow coming out of the VC was about 60% plugged this winter... I cleaned it up with some brake cleaner, hoping to not cause some kind of stroke somewhere else in the CCV. So far so good.

Zero consumption, btw.

 

[Quattro Pete]

Originally Posted By: antonmnster
but already has a history of leaving a fair amount of sludge in my engine.

Semi-annual oil changes and still getting sludge? How many miles do you put on during this time? Something's not right.

I do annual changes with GC (about 10k miles) and don't have any sludge issues.

 

[Craig in Canada]

My dad's 540 running BMW 5W30 at half-intervals (ie. change the oil twice in the OLM period) had lots of discolouration, varnish-like buildup, lifter ticks, VANOS knocks and all kinds of stuff going on.

One round of ARX (older, shorter, gentler instructions) and switch to GC and it was GREATLY improved.

I've heard people praising the BMW oil and running it full intervals but I/we certainly weren't impressed by our experience. Unless, of course, the dealers wasn't putting BMW 5W30 in. It's doing the characteristic "Castrol red" staining, however.

 

[Oldwolf]

Who makes the BMW oil?

 

[Quattro Pete]

Originally Posted By: Oldwolf
Who makes the BMW oil?

Castrol/BP.