I have always been a Castrol oil man but after reading (searching here and on the web) that Castrol Synthetic oils are not "full Synthetic" in the States, so i am going to do the switch (hard to do...lol) for my X5. I went to Mobil's web site and read that Mobil 1 0w-40 http://www.mobiloil.com/USA-English/...l_1_0W-40.aspx (below was copied/paste from Mobil web site).

Mobil 1 0W-40 meets key industry and car builder specifications for:

• Mercedes MB 229.5

• BMW Longlife 01

• Porsche Approval List 2002

• VW 502.00/505.00/503.01

• GM-LL-A-025 (gasoline)

• GM-LL-B-025 (diesel)

• ACEA A3, B3/B4

• API SM/CF

I was wondering what does BMW Longlife 01 mean? Also will 0w-40 oil be good for temp that are below -20 F. I live up in MN and we do get weeks of -20 F (sometime not including windchills).

Oil Changes: Does anyone know were i can buy oil drain plug washers. Can i get them at the Dealer or any good BMW online stores (for air filters, and etc). On my 93 Range Rover i needed a crush washer but did not know if X5's had them or not.
Cheers,

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2001 X5 3.0i "Dodi"
1993 Range Rover County LWB (71,600 miles) "Bertha"
1991 Range Rover parting out