2004 buick lesabre 72000 mi uses oil approx one quart after 1600 mi.using synthetic. should oil level be maintained at “full” between changes
This rate of oil consumption is completely within normal limits–even for a new car.
As a result, I suggest that you not lose any sleep over the issue.
And, yes, you should maintain the oil level as close to “full” between changes as possible.
I am an advocate of adding oil once the dipstick shows that the level in the crankcase has fallen by 1/2 qt. Just be sure to add slowly, so as to not overfill the crankcase.