Always one quart low

[DK]

When do you check your oil? After it sat for a quite some while or quickly
when filling up at the gas station? After how many miles do you notice that
your low on oil?
Do you do your own oil changes? If so, I would assume that you double check
that the oil is at the MAX on the dip stick?
If there are no obvious leaks, you might be burning it? Either the turbo or
valves... you didn't mention any signs of burning/ blueish smoke from the
exhaust.