Oil puddled on the ground often looks like more than it is. If there were no additional warning lights beyond the check engine oil level, then it is more likely that it didn't run out of oil. First, see how low it is. Add oil back until it is on the dipstick.

Look under the hood and see if it is obvious where the oil came from. If so, describe it to us. If not, book it in with your mechanic.

Good luck.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue