oil consumption

I have to ask: what makes you certain that your car is not consuming oil? If there is no oil leaks at all, then it has to be going somewhere. Actually, a quart every 1000 miles is still within the manufactuers specifications. Most car manufactuers have about the same specification: 1 quart every 600-1200 miles. If you are really interested in diagnosing where the oil is coming from, pull each spark plug and closely examine the electrodes. I really think that your concern is very typical though.

Indeed, as b-glaste says indicated - Ford considered "normal" one quart burned every 700 miles or more for vehicles of your model year. Nonetheless - the 4.6L V8 is known to "consume" oil if oil change intervals are not quite frequent enough historically. Being that the vehicle is now 15 years old -- anything goes.