I've been using conventional oil since I purchased my car (last year). I recently (1000kms ago) changed to synthetic 5W30 oil. I check my oil level periodically and noticed yesterday that my level went down about a 1/4-1/3 litre. Is this normal? I understand during my break-in period my level went down about 1/2 litre...but that was when I had about 3000-4000kms on the odometer. I now have about 20,000kms. Does the engine go through a "secondary" break-in period when changing to synthetic oil? Does synthetic oil have a tendency to burn more often than dino oil?