My experience has over the years has been that some very good engines NEVER use a drop of oil over a 5,000 mile change interval and some other very good engines may use a quart of oil every 1,000 miles or so.

A part of the difference is driving style.  Driving 80 mpg across a Texas highway in August will consume more oil in a "healthy" engine than driving 50 mpg across California in March.  But, much of the difference is just the luck of the draw.

I currently have a vehicle that has always used about a quart of oil every 1,600 miles.  So, every 800 miles or so, I add 1/2 quart of oil.  I prefer to keep the oil level close to full, rather than run a full quart low.

My usual oil is a 5w-30 oil.  I experimented with using Mobil I 10w-40 "High Mileage" oil and cut oil consumption by half.  But, the engine, using 10w-40 oil uses about 1% more gas than with the 5w-30 oil.  So, there is a trade-off either way.

As long as your engine needs less than a quart every 1,000 miles or so, I would not worry about it.  Just check your oil level every 500 miles and add some oil whenever you get to be a quart low.

One advantage of adding oil...oil analysis from Blackstone Labs shows that the additives from "fresh" top-off oil restores the additives in your oil that protect against sludge formation.  Because I add about 2 1/2 quarts of oil between changes at 5,000 mile intervals, almost half of the oil in the engine at 5,000 miles is "younger" than 5,000 miles...the "average" age of the oil is closer to 3,000 miles, and the oil has the clear gold color of new (or newish) oil, not the dark black color sometimes seen after 5,000 miles.
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