New oil filter at every oil change (Focus Turnier 1)

Remember: oil filters are wearing parts that need to be replaced regularly. Regularly means every time you change the oil. A clogged oil filter allows engine oil to pass through the high-pressure valve into the engine, bypassing the oil filter, but dirty engine oil accelerates wear of the entire engine - especially the working surfaces of the pistons and cylinders, camshaft and crankshaft. In the standard case, engine oil gets through holes and channels to the appropriate lubrication points in the engine block and crankshaft, and in a similar way it also gets to the camshaft(s) in the cylinder head.

Most other lubrication points, such as the piston and valve train, are satisfied with the normal lubrication supplied by the injection caused by the rotation of the crankshaft and camshaft: both shafts swirl the oil in their surroundings, which emerges at the lubrication points. During its orderly journey through the engine, the oil not only maintains the mobility of all internal components, but also removes most of the excess heat that is generated in the bearing journals and during each working stroke. On the way back to the crankcase, the oil does not have to work so hard: it flows back into the crankcase through special return channels. Here the oil "calms down" for a short time and, before being put under pressure again, cools down to about 75°C.