94 Excel - burning 4 qts between changes, no drips

I am driving a loaner car from a friend - 94 Hyundai Excel. I changed the oil 2 months ago when I got it, refilled with 4 full quarts, new filter. Today (2 months later) the oil light comes on. I check and there is NOTHING on the dip stick! I added until it showed up at the right place on the dipstick - almost 4 quarts.

But there have been NO leaks in my garage! Give me the lowdown... good, bad or ugly!:confused:

How many miles did you cover in that time? Using oil fairly fast without losing any onto the driveway or coating the bottom of the car would likely be bad piston rings. Even worn oil control rings shouldnt result in that much however. I could imagine a defective PCV valve might be allowing too much vacuum in the crankcase, and increasing oil consumption. Have a look at the spark plugs. They should be very light brown - like beige- and all about the same color. If they are darker - its likely worn rings on all cylinders. If one is much darker than the others, it could be a broken piston ring.
On the other hand, if the car is running okay, oil is lots cheaper than engine repair - even if you do the work yourself.