Just change your oil and filter every 3K and be done with it! I just retired a 4 cylinder turbo Mazda with 300,000 miles on it which did not burn any oil. Never opened the engine at all. Original turbo. Retired due to electrical problems.
Any well designed engine will probably provide more miles than you care to keep it for if you just follow the manufacturer's recommended schedule for maintenance, and, in the case of oil changes, go them one better and change it at 3K. Or 5K, or whatever makes you feel good. 3K makes me feel good.
In the big engine biz we change oil based on running hours and oil analysis. Typically more than 2000 hours on oil. In a car at an average speed of 40 MPH, 3000 miles is only 75 hours on the oil. So chances are it's gonna be fine and not "worn out".
And the Mazda? I used Dino oil.