Oil consumption.

High oil consumption in engines can be caused by several factors:

1. Worn Piston Rings: piston rings that are worn or damaged can allow oil to seep into the combustion chamber and burn, leading to increased oil consumption.
2. Valve Seal Wear: aging or damaged valve seals can cause oil to leak into the cylinders.
3. Oil Leaks: external oil leaks from gaskets, seals, or other engine components can contribute to high oil consumption.
4. PCV System Issues: a malfunctioning Positive Crankcase Ventilation (PCV) valve can lead to oil being drawn into the intake manifold and burned.
5. Overfilled Oil: adding too much oil can cause it to be forced into areas where it can be burned off.
6. High Engine Temperatures: excessive heat can break down oil faster, leading to higher consumption.

Engine additives can sometimes help reduce oil consumption by:

1. Sealing Leaks: certain engine additives can help condition and swell seals and gaskets, reducing leaks.
2. Improving Viscosity: engine additives can enhance the oil’s viscosity, making it less likely to seep past worn components.
3. Cleaning Deposits: engine additives designed to clean the engine can remove sludge and deposits that might contribute to oil consumption.

However, while engine additives can provide temporary relief or mitigate minor issues, they may not fully resolve the underlying causes of high oil consumption. Persistent problems typically require mechanical repairs for a long-term solution.