Sudden High Engine Oil consumption - '85MB-190e

With approx 100K miles on the clock, the engine suddenly began to use approx 1qt of oil for every 600 miles. Prior to this, the dipstick typically read a shade under 1 qt low at every service interval (5000 mi)

I can't imagine its suddenly broken a oil ring... there has got to be a vaccuum port pulling oil over somewhere...

Any thoughts?