Adding half quart of oil between oil changes?

[Moc5Mazda]

Recently I have been looking at this Mx-3 and the lady who own's it says she adds a half quart of oil in between oil changes. The car doesn't smoke or show signs of oil lost. So where does all this oil go? Is there a place on the car that I should look other than the normal spots or is the lady just stupid? The car is a 95 dohc L4

[mitmaks]

check spark plug boot wells, valve cover gasket..

[guyaverage]

I change my oil every 5k miles using Mobil 1 and my '93 SOHC has used one-third to one-half quart between changes practically since I bought it new. No leaks, no smoke, no drips, spark plug boot wells are dry, valve cover gasket is holding strong, etc. I have 125,000 miles on the original catalyst and at the last emissions check the CO and HC emissions were rediculously lower than what Ohio allows ( which admittedly is quite elevated). Whatever oil the engine is burning is being cleaned up by the catalyst. This will shorten the cats life some but that would be a great excuse to get a high-flow whenever you end up needing new one. Ask her how long its been doing this, if its been long term (30,000+ miles) I wouldnt worry about it.

[tinkertank]

Engines just naturally use a little oil. The older they get, the little more they use. There is always a tiny little amount of blow-back and seepage from the cylinders and elsewhere: <p>More than you ever wanted to know about motor oil