Toyota Repair: 97 Tercel Oil problem, excessive oil consumption, engine restorer

Question
I have an automatic 97 tercel white hawk with 180000 miles on it.
Cant figure out what is happening to the oil. In two weeks time, it loses oil ....the entire length of the dip-stick cross-hatch pattern...problably one quart. Have to keep adding oil each week. Never noticed a leak so it must be burning oil but there is no blue smoke either. Cant figure it out. I have another '97 Tercel with 97000 miles that is a stick shift and that never loses any oil.
Do you have any ideas ? Would the additive "Engine Restorer" work ?

Thank you,

vb

Answer
I don't believe in additives, they are a temporary fix at best. Have you checked the coolant for the possibility of oil entering the cooling system? Remove the air filter and see if any oil is in there, in most cases of excessive oil consumption it's because the piston rings are worn in which case the engine is burning the oil, the oil has to go somewhere and there are no leaks as you stated.