On our x5s, the oil light comes on about 2 qt low. It is at least 1/2 qt below the dipstick when the light comes on. That said since it holds 8 quarts, that's like a normal car being 1 qt low.

Our cars both let you know when oil is starting to get low because it takes a few seconds for the valve noise to disappear on cold start. Full of oil takes 3-4 seconds but about 1 q low starts to take 10-13 seconds, and the oil pressure light takes an extra second or two to go out.

When I can count to 12 before valve ticks go away then I know it's time to get a bottle of Mobil One.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)