That's 2 million years as unrefined crude...
...what about all of those additives and such in refined oil? The oil may not break down, but how long does the chemical bonding of the ancillary compounds stay intact?
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car