BMW's oil has for the last 20 years been exclusively Castrol re-branded. To answer why the interval is 'shorter' in the US may have something to do with the additives in the fuel here.

nope - it gets sent to a lab

doesn't really age like it would if in a running engine and even then the only real chemical reactions occur would be oxidation brought on by high heat, water, fuel dilution, some yellow metal to catalyze, maybe coolant if your so unlucky. Some of the oxidation can be minimized by the acid neutralizers found in the oil but at some point they get used up. When its formulated right it does a fine job at establishing a film between the moving parts and as temp increases, the surface active agents that help with wear kick in to form a layer.

Everything has a shelf life but motor oil is a few years easy - say 3 to 7.

That's a very severe lubrication regime upon start-up. That main bearing most likely has the most stress upon it. Not sure about the BMW but until the bearing has established what is called hydrodynamic film formation its at the mercy of boundary film and that is where the most wear occurs during start-up. If you have a tendency to rev you engine at start up your not giving the oil a chance to separate the babbit surface. The more revs with out mixed film or hydrodynamic film and the more times the semi-lubricated surface is presented...more wear sooner.

Its a good reason to not rev the engine at start-up.

While it is possible for engine oil to shear down, I have seen it mostly when oil blenders try to achieve a 0W30 or 0W40. Normally you can't get that sort of a cold crank viscosity and a high operating viscosity without the use of viscosity index improvers and thats what will shear under harsh conditions. They are polymers that are not always shear resistant compared to the base oil which is a polymer but is far more shear resistant. defing harsh conditions? Now harsh conditions may bring up images of the Oil Sands in January or the Mojave desert in June. But actually how folks start their engines can have just as much damage. Contamination can do it as well.

Blackstone is a funny lab. They tend to paint various problems with a very broad brush. They are not at all active in STLE or ICML compared to other labs which is a red flag. They don't have the confidence of the major oil companies because they tend to simplify conditions and blame the oil. Frankly, only about 5% of any failure can be traced to the oil. If fact its most likely less then that.

It seems reasonable to say that cars need to be driven until hot, and not just driven for short stints before being put up. Blow by past the rings is what causes much contamination, and cold oil is not hot enough to cook out those contaminants.

Driving your garage queen down to pick up a newspaper a few times a week, or idling in the driveway isn't the way to go. Take a long drive, and your oil will distill out the water and fuel. When those vapors accumulate as liquid in your oil, that is when the interesting and fun things start to happen.

The tell take sign for many is the yellowish emulsion that forms on the filler cap. So drive your car, don't baby it.

Panorama just had an interesting story on an car with variocam that did not operate properly because the owner put in too heavy an oil. Once they changed back to the recommended weight the variocam worked. Turns out the small sliding pin couldn't move due to the high viscosity.

The point being, BMW probably knows a lot more about the needs of the engine. Seems odd to save money with oil changes. Unfortunately the owner clouded the warrentee story by not following the recommendations.

10w-60 does seem amazingly thick for a water cooled engine. Especially when Honda and the other makers of high revving engine specify 0w-20. It implies BMW expects the oil to get hot enough to need the capability of a 60 weight. That's really hot! In a water cooled engine?!?

For our air/oil cooled engine 10w-60 might be appropriate. But you better warm it up before flogging it. The oil cooling of the heads really pumps the heat in, as well as the piston crowns and cylinder walls.

So what I gather from this:

1)- shear is not by design, but a fault.

2)- Blackstone oversimplifies matters.

Next question: If oil is discovered as sheared- IE 5/30 to 20WT- does that mean change oil time?

rjp

Yes, and it's documented SOA kills you for using it. It's for Diesel Engines. They do not approve.


The NASIOC standard response to that is armchair legalese. In real life, you get stonewalled and a turndown for warranty claim. At the end of the day, it's on you.

Google.

rjp

Just to update this old thread. It took me a while to get this one apart. The customer is out of the country, and I knew the warranty company would stall my work, so I waited till I slowed down, and could afford to tie up a rack for a few weeks while the stroke me around .
They made me remove the motor, and pull it apart. It spun # 6 rod bearing, and tore up the crank pretty good. It was full of clean oil, and he had all records for past oil changes 2 within 10,000 miles to be exact. Both were non synthetic motor oil.
To my surprise, the warranty company approved the claim, and have shipped me a used engine to install . They will pay 100% of the labor, and the cost of the motor, minus the time I had in pulling the motor apart, and a few hours spent with an adjuster .
The owner of the car is stoked, and I was really surprised the warranty company took care of it .

Great. I hope the used engine is OK.

How does the used engine look? What kind of warranty is given on those?

I understand that he is going from one use engine to another, but that other one is a complete unknown.

All I can say, is they guy is low on funds, and this is what the warranty company offered . A new 3.0 From BMW is 19k. Owwieouch !!
I was going to try to sell him on replacing the rod bearings while it is out and on the stand, that is what I would do if it were my motor.
The new motor has similar miles, and is coming from LKQ . It is the only real option for repairing this car that is financially sound .

Replacing the rod bearings would be cheap insurance. Smart.

Will they let you keep the old motor? Any decent parts on it that will cover the unpaid time if you sell them?

Funny you should mention that. Yes, I get to keep the old motor. But it is the customers responsibility to pay for the diag time . I make sure they know that up front, and if the warranty company declines to authorize, they are still on the hook for removal, and teardown.
This customer is a great guy and paid me up front for his portion. He will most likely get some of his some money back if all goes smooth .
I don't know if there is a huge demand for low end parts from a modern BMW, the crank and one rod is junk. The rest look decent . I am sure the head , and valve train may be worth a few bucks

I don't believe in extending oil changes past 3500 miles, synths and minerals both break down at the same rate. Thinking one is better than the other is just silly, they do the same job. Now I would be nervous about recycled oil, that's just a personal belief of mine. You can go to the nitty gritty and follow the owners manual, that's ok. Of course its a Bimmer, and those things are ragged out by owners on a daily basis. I see bimmer ragging all the time, cutting me off to catch a green light, stupid pricks! LOL!http://forums.pelicanparts.com/uploa...1481899877.jpggood luck bro!

The local FCA dealer extends the factory drivetrain warranty to the life of the vehicle if they do the oil change and tire rotation. They change the oil every 6k miles on new cars. This is still long before the oil monitor would tell you to change the oil. Our truck is 7500 miles per the owners manual. I change that at 6k as well.

We have a VW dealer near Phoenix that does this. But they are pretty far out and it'd be a real headche to get there for this kind of routine maint. I wonder how this deal pencils out for them.

They are 11 miles from us and in the town where we get groceries and stuff so we are there often enough. The first few years they threw in oil change/rotation for free. The price on the car was in line with the others in the area so I am guessing they make a lot on the car after those free ones are done. $19.95 for tires and $14.99 for oil so $35 a pop every 6k miles is pretty good. We have $42k on the car now and have a few free ones left so if we keep the car for 100k miles they will get 50kish miles worth of oil changes. We keep cars a while so they might get 150k miles of for pay changes from us. That is what $875 or so?