Engine Oil Grade ???

[BimmerDude]

Hello to all again, my good friend and I were talking about engine oil types. He says that by using reg. engine oil and changing it every 2500 to 3000 miles is just fine in my X5. But I told him, then why does the manufacture request synthetic? Can anybody give me some info here as to the oil types. And if reg. castrol oil is just as good if you change the oil every 3k miles, versus the synthetic which is stronger but for obvious longer intervals... Does it really matter? Any info would help to put my buddy in his place... Thanks....

[KUCAK]

I was also told that by a few mechanics.

[DipnX5]

Could it void your warranty? Also a great article on this subject:
http://www.bimmerforums.com/0w30/

[The Cleaner]

You can put regular oil in you car if you like and change it every 3k. BMW uses synthetic because the change interval is 15k and if you use BMW - LL04 you save about 18 liters of oil (at 3 bucks a liter thats 54 dollars) and about 30 bucks in filters.

4 Changed will cost about 120.00 in parts with regular oil.
1 change with Synthetic will cost about 50 bucks.

It's up to you.

[BimmerDude]

Thanks Cleaner, I guess my buddy was right. I was thinking of putting synthetic and changing every 5k miles.... This way I can get better protection, but either way you look at it, I'm truly saving a lot more by doing changes every 5k or 6k, versus 3k with reg. oil... Thanks again for your expertease....

[X5 in AK]

I agree, use synthetic and change every 5k miles. Oil is cheap compared to the cost of a new engine!!!! 15k is WAY to long to keep oil in an engine, even if it is synthetic.

[BimmerDude]

What about this 0-w30? What does this 0 mean??? Just curious since we are on the topic... Thanks...

[X5 in AK]

0W-30 is good for winter, ie, cold temps. The 0 (first number) refers to the viscosity of the oil at room temp, the 30 (second number) refers to the viscosity at hot (operating) temps.
Therefore a 15W-30 oil will be more viscous (thicker) at room temp than a 0W-30, yet theoretically the same at operating temp. And a 0W-60 (what BMW recommends in the M3 engine, I think) will be even more viscous (thicker) at operating temps, good for keeping the oil on critical parts like cylinder walls and cam lobes, yet still be nice and thin at start up.
A non-syn 15W-30 or -40 won't even pour out of the bottle at temps below about 20 F. A syn 15w-30 will pour a bit better at cold temps. For winter use, a syn 5W or 0W is absolutely required. I could cold start my dodge cummins diesel at -40F with syn 0W-40 in it. An engine won't even turn over at -40F with a non-syn oil in it.

Anyways, for general summer use a syn 5W-40 is good. A 0W-30 or -40 probably isn't necessary unless you are seeing lots of below zero temps. But, one could make the arguement that a 0W-40 is better cuz you get better lube at start-up.

There is lots of info out on the web about oil grades and viscosities, I thought I had some stuff bookmarked, but can't find it.

And I'm sure that everybody else has a different opinion on all this, but that's my take on it!!

[AzNMpower32]

Basically, it's the viscosity. I'm no pro on the subject, but read X5 in AK's post. Thinner oils are better in colder temps due to easier pumpability (cuz they're thinner) and there's just the slightest fraction of better fuel economy. However, you want a thicker oil in high temps in order to better protect the engine from thermal breakdown and stuff like that.

I think the S54 engine in the M3 uses 10W-60, which you can only buy at the BMW dealer. Makes sense, seeing how it's such a high compression, race-derived engine.

[Dima1978]

Regular oil has wax and all other mineral stuff -- bad for your gaskets. Synth is a better choice-- go with it. About 8 years ago I 've seen a comparison test in a magazine-- some wax based(not true synth) Shell oil has been rated best, mobil1 second(loosing by a little, but true synth), etc. I believe it was a test for Euro brands (Royal Purple and Amsoil weren't present).