Oil Additive Question

Most of the time, worn seals are the issue-an experienced mechanic can determine if the oil burning is due to worn seals or worn rings/scored cylinder walls. It involves checking the compression in each cylinder-then squirting in a bit of engine oil-if the compression comes up, it is worn rings or scored walls. This is a rare condtiion-most of the time, it is the valve seals. Replacing these is pretty cheap-for a 4 cylinder engine , usually $300-$400 (depending how accessable the engine head is).
Now for the fun: sometimes, an old-time mechanic trick will work-but it is a dangerous procedure (add too much and you can destroy the engine). The procedure is to add a few ounces of brake fluid to the sump-the brake fluid will soften the seals and cause them to swell-temporarily stopping the oil burning.
This works…sometimes. If you want to keep the car, i’d go the replacement seals route (if the rings are still good).