Cars that sit in dealer inventory lead tough lives. Frequent starts and short running time can cause crankcase fuel dilution, and since the typical 90 percent distillation curve of gasolines is about 300F, once these heavy, high boiling point components mix with the oil, they will stay until the oil is drained.

Suggest you run an analysis of the new oil when you change it or before. Assuming you are driving the car "normally" i.e. trips of sufficient length to fully warm up the engine - including the oil, not just the coolant, you should see much lower fuel dilution.

If you've accumulated over 10K miles in six months I suspect your average trip length is above the average for most cars.

Duke