Defying BMW's oil recommendations!

[fdcg27]

Well, not exactly, but given what I'm trying in it, that seemed too good a thread title to pass up.
I am defying BMW's viscosity recommendations, since according to the OM, a 10W-40 is too thin for current ambient temperatures as well as those we'll see over the next few months.
I've done seven runs of FAR Nextgen Maxlife in this engine, and had a very nice UOA of the third run.
I decided to try FAR Defy.
I'll do three runs of it and UOA the third. The car will be run under similar conditions, so the results should be pretty comparable.
It'll also be intersting to see whether traces of sodium from the Valvoline still remain after 4K+3K+4K on Defy.
Also, I'll get to see whether I've been sucessful in diagnosing and reducing the fuel dilution I saw in the Maxlife UOA.
Finally, this will be instructive in any discussion of which HM is better, at least in this engine as I use it.

 

[Merkava_4]

Originally Posted By: fdcg27
I am defying BMW's viscosity recommendations, since according to the OM, a 10W-40 is too thin for current ambient temperatures as well as those we'll see over the next few months.


What does the OM recommend then ? I would think 10W-40 would be good for a BMW.

You wanna defy BMW's recommendations ? Defy the 10,000 mile OCI !!

 

[fdcg27]

For summer temps, BMW actually recommends a 20W-50.
I'm sure that you'd approve of that.
The MM of my old car will allow for surprisingly long drains.
The longest I've run is 6K on Mobil 1 15W-50.
The UOA I did with Maxlife 10W-40 was 4K and showed 2.9% fuel dilution under warm weather conditions with almost no trips of less than twenty five miles on a cold start, so I think that short drains are probably a good idea with this engine.

 

[Merkava_4]

Originally Posted By: fdcg27
For summer temps, BMW actually recommends a 20W-50.
I'm sure that you'd approve of that.


I might have to get me one of those BMW's. It's a 1995 you say ?

 

[fdcg27]

20W-50 was recommended for lots of German cars for warmer weather over a number of years.
BMW actually recommended this grade for ambient from about 14F to 120F in the OM for my car.
An all climate motor oil, in other words.
I used 20W-50 as the warm weather fill in our last old Mercedes, per their recommendations, and it seemed fine.
You'd never have known that such a thick oil was in the sump unless you looked at the empty bottles.
There are those who think that 20W-50 is engine death in a bottle, but I've found it to work well when I've used it.
It's just that the grade really doesn't have all that many applications that actually need it.

 

[Merkava_4]

Originally Posted By: fdcg27
There are those who think that 20W-50 is engine death in a bottle, but I've found it to work well when I've used it.


They look at the numbers and they think it's almost as thick as grease. Go into an auto parts store and shake the bottle, it'll slosh around freely just like an oil should.

 

[fdcg27]

Yeah, and get a bottle out of the garage in the dead of winter and it'll slosh around just like honey.
I doubt that real winter computes for you, given where you live.

 

[Merkava_4]

Originally Posted By: fdcg27
Yeah, and get a bottle out of the garage in the dead of winter and it'll slosh around just like honey.
I doubt that real winter computes for you, given where you live.


The thickest I've ever seen motor oil was 10w30 at +19 F. But I had to put it in the freezer to get it there.

 

[fdcg27]

We had one -12F morning this past winter and we've seen mornings as cold as -27F here, although that is rare enough to be a record.
Interstingly, I started a '76 Civic full of 10W-40 on a -25F morning after it had sat outside all night.
No issues then or over the next 40K or so we had the car.
Thin may be better under very cold conditions, but thick isn't death to an engine either.

 

[Merkava_4]

Yeah the guys that cringe at 20W-50 are probably the guys living in real cold areas. The lowest temps we get here in Central California during the wintertime is +17 F but that's only for a short period of time between 4:00AM and 6:00AM.

 

[fdcg27]

That doesn't even count as cold.
After a few below zero mornings, 17F feels pretty moderate.
We had an awful winter, although the previous two were very moderate.

 

[Dave Hess]

If you drive 'normal' I would not use 20w50.

 

[Merkava_4]

Originally Posted By: LT4 Vette
If you drive 'normal' I would not use 20w50.


And where do you live at sir ?

 

[KCJeep]

If you want to use 10w40 in your BMW and don't want to get too crazy with your departure from 20w50, Pennzoil High Mileage and Castrol 10w40 are both above average "thick" 10w40's.

But I think you'll do very well with the Maxlife or Defy.

 

[Stelth]

Isn't 20w-50 solid at room temperature?

 

[fdcg27]

The car did just fine on Maxlife and should on Defy as well.
I think BMW'd recommendations in 1995 were based in part upon old-school thinking and in part on the potentially greater shearing of the oils of the time.
The Maxlife I UOAed did shear to a thirty in just 4K and the MM will allow for pretty long drains if you follow it. BMW therefore probably thought that a 20W-50 would be a safe recommendation for warm weather for the longer drains that the MM allows.

 

[Merkava_4]

Originally Posted By: fdcg27
The car did just fine on Maxlife and should on Defy as well.


Have you tried MaxLife 10W-40 in it ?

 

[Benzadmiral]

With my W126 V-8 Mercedes, when I lived in Denver I used Valvoline 20W-50 in summer (which could get hot!), and 10w30 in winter. Lows could get down to 9 deg. F. The car had no trouble starting.

When I came back to Da Swamp I switched it to 10w30 all year, and later 15w40. Again, no issues.

 

[SilverC6]

I'm sure after warranty considerations are over, there are plenty of oils that would work well in a BMW.

Even when new, I don't think the LL-01 stuff would be necessary if you changed the oil at sane intervals.

On the 20W-50 thickness, I tried to pour some into my '11 Toyota Camry once and it was too thick to fit through the fill hole.

It just cascaded down the valve cover onto the ground.

I went through three quarts before I figured out what was happening.

 

[fdcg27]

Originally Posted By: Merkava_4
Originally Posted By: fdcg27
The car did just fine on Maxlife and should on Defy as well.


Have you tried MaxLife 10W-40 in it ?


I tried Maxlife 10W-40, but after 4K, I was trying Maxlife 10w30, or at least that's what the used oil analysis showed.
Really good wear metals levels, FWIW as well as strong TBN retention.
I'm too lazy to find it right now, but I posted it in the used oil analysis forum in August 2012.