Using a little oil between changes? on 1999 Volvo V70 XC

My Volvo V70 XC uses about a quart of oil between changes. The car has 143,750 miles and seems to run and operate great. Just a little concerned because it has a turbo, and I don't want to overlook something that might be more serious?
I have crawled under the car and there is no apparent leaking, so I am curious if it is fairly normal or something to be concerned about?

Asked by for the 1999 Volvo V70 XC
I'd get the PCV system checked. The oil separator with the vent hoses may need to be replaced, it's a common problem at over 100K miles.
There is a venting banjo bolt to the intake ( a coolant pipe wraps around it) which tends to clog and creates high crank case pressure, therefor higher oil consumption. The best thing would be to replace the oil separator box with the attached hoses and clean all the ports.
The intake manifold has to come off to get access.

1 more answer , 1 more comment
Oil useage as a car (specifically the engine) ages is normal. As internal engine wear accumulates, blow-by increases and more oil is burned/used.
Turbo-charged engines are harder on the oil (due to excessive heat degredation) and have higher combustion chamber pressures which can also accelerate engine wear and increase blow-by.
Thanks, I am somewhat of a "shade tree" mechanic, and if this were the 305 Chevy motor in my 1988 Trans-Am I would just be happy it was still running and only using about a quart of oil between changes, but the 2.4L 5 cyl. with turbo, I just didn't want to miss an early warning sign. I have crawled all under and looked all over and I don't see any leaks anywhere. thanks.