Oil Change for E53 X5 4.8is

[Weasel]

Correct, the OEM BMW oil is fully synthetic 5w-30, and BMW does recommend castrol. It takes about 8 quarts too. (she's thirsty!)

[Weebie]

Originally Posted by weasel56

Correct, the OEM BMW oil is fully synthetic 5w-30, and BMW does recommend castrol. It takes about 8 quarts too. (she's thirsty!)

Is that what you use for your beast weasel56? How much does one bottle of the OEM BMW 5w30 fully synthetic oil cost? Is it cheaper than Mobil 1 0w40? I assume I can't go wrong with either? Are there any advantages with using 0w40 instead of 5w30? I currently reside in Canada so we encounter warm and cold temperatures.

[Weasel]

Originally Posted by Weebie

Is that what you use for your beast weasel56? How much does one bottle of the OEM BMW 5w30 fully synthetic oil cost? Is it cheaper than Mobil 1 0w40? I assume I can't go wrong with either? Are there any advantages with using 0w40 instead of 5w30? I currently reside in Canada so we encounter warm and cold temperatures.

I use the BMW oil as it is convienent for me working there and all, and don't remember the price off hand, but it should be about the same per quart as any top brand full synthetic.

As for the ow-40 vs 5w-30, the second # is the viscosity at full cold (ambient temperature) and the 1st # is the operating temperature viscosity. Being where you have extreme colds (at least vs the mild south I'm in where the shop had the AC on today)... The 40 weight would be thicker than oem at cold, but thinner when hot. It seems to me the 5w-30 would be better. Maybe someone with more cold weather/oil knowledge will chime in though.

[JCL]

Originally Posted by weasel56

I use the BMW oil as it is convenient for me working there and all, and don't remember the price off hand, but it should be about the same per quart as any top brand full synthetic.

As for the ow-40 vs 5w-30, the second # is the viscosity at full cold (ambient temperature) and the 1st # is the operating temperature viscosity. Being where you have extreme colds (at least vs the mild south I'm in where the shop had the AC on today)... The 40 weight would be thicker than oem at cold, but thinner when hot. It seems to me the 5w-30 would be better. Maybe someone with more cold weather/oil knowledge will chime in though.

I use the BMW 5w-30 oil as well, and find that it is a similar price to other oils. It is convenient since I pick up a filter at the same time.

The viscosity numbers are backwards, above. A 5w-30 acts like a 5 weight oil during cold starts (tested at 0 C), and like a 30 weight oil at operating temperatures (tested at 100 C). Thus, the 0w-40 is thinner than the 5w-30 when cold, not thicker. However, the 5w-30 oil is fine at the temperatures the OP is likely to reach (depending on where he is located). The pour point is probably around -50 or so. At -40 and with cold starts I would be looking for a 0w oil, as it isn't just a matter of the pour point, the oil will be thicker at lower temperatures. You have to start looking at other test criteria then.