- excessive amount of oil leads to its greater consumption, because excess oil is blown into the engine through the crankcase ventilation;
- liquid oil burns faster than thick oil. Seasonal oil becomes liquid like water when heated, and its consumption increases accordingly. All-season oil remains thick; this results in lower fuel consumption - this is especially noticeable on long trips;
- all-season oil that remains in the engine for too long becomes slightly thinner, losing its highest viscosity grade, and the need for additional oil increases accordingly.
- a sharp driving style at high engine speeds, in addition to increasing fuel consumption, also increases oil consumption. This is especially evident when a new engine immediately begins to operate at full load.
- during break-in, the engine needs a little more lubrication than usual.
- leaks. Check everything as described in the chapter Engines.
- defect in the engine itself; for example, defective valve stem gaskets, too large a gap between the valve guide and the valve stem, defective piston rings or their incorrect installation during repair, damage to the cylinder wall due to wear or piston scoring.
Lack of oil consumption is suspicious
In winter, when driving short distances, it happens that the oil level does not decrease from measurement to measurement, but even increases. There is no reason to rejoice here, since this means that the engine oil is diluted with fuel or water condensate. These "additives", which significantly worsen the lubricating qualities of the oil, need to be "boiled out" by regular long-term driving so that the condensate evaporates. Then you need to immediately measure the oil level, since after evaporation of gasoline or water that got into the oil, its level will drop sharply! When driving exclusively in extreme urban mode without intermediate long-distance trips, it is recommended to change the oil more often than the above intervals, for example, every 3000 km or once every four months.
In winter, oil consumption of 2-3% should be taken into account, while our injection engines contain less gasoline in the oil with a metered enrichment of the working mixture during cold engine start-up than in old carburetor engines.