Oil consumption, measuring
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Oil consumption, measuring
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The oil consumption in a combustion engine is the amount of oil that is used during the combustion process. Under no circumstances should oil consumption be confused with oil loss, which is due to leaks from the oil sump, camshaft cover, etc.
What engine oil does:
The function of an engine involves a certain consumption of oil. The expectation that has often arisen during the development of the internal combustion engine - making an engine that does not consumer any oil - is completely unrealistic. External running conditions, driving characteristics and production tolerances all affect oil consumption to a certain degree. It is necessary to ensure that the oil level does not drop below the MIN mark or rise above the MAX mark on the dipstick.
Although a certain degree of oil consumption is technically impossible to avoid, oil thinning caused by special running conditions will make it appear that no oil is being consumed at all. Lots of cold starts, driving with a cold engine and so on, means that the oil running back to the oil sump will take with it fuel with high boiling point and condensation residue that will "dilute" the oil. This will lead to the wrong supposition that the engine is not using any oil.
Oil that has been thinned in this way will lose its lubricating properties and can cause engine damage unless the oil is changed at the prescribed interval. Lots of urban driving and short distances with a cold engine is the main cause of oil thinning.
Since oil consumption does not stabilise for a few thousand kilometres, measuring the oil consumption will not give a reliable result until after about 7500 km. Before measuring consumption, it is important to check that the engine is not leaking any oil.
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Note
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The dipstick has only a control function and cannot be used for measuring purposes. Principally, the engine must have been turned off for 2 min. before checking the oil level. Should the maximum engine oil fill volume not agree with the maximum level on the dipstick after an oil change, then it is probably due to manufacturing tolerances.
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All information on permitted engine oil consumption and filling volumes can be found in the owner's manual
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1.
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Check the level with the car standing level and with warm engine (engine oil temperature min. 80°C)
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2.
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Drain the engine oil straight after turning off the engine - draining time approx. 30 minutes (tests have given this time)
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3.
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Measure the volume of drained oil with a 6 litre graduated cylinder and fill with new oil to max filling volume minus the volume of the engine oil filter, which has not been changed.
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4.
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With this amount of oil, the customer should be able to drive at least 1000 km, of course without having to top up with more oil (normal terrain and normal driving style)
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5.
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The above procedure (points 1 and 2) is then repeated with exactly the same drain time for the engine oil
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6.
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The engine oil volume that is now "missing" from the graduated cylinder is the consumed engine oil/mileage.
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Oil consumption is calculated in the following way:
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filled oil volume (I) - drained oil volume (l)
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x 1000 = oil consumption (l/1000 km)
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actual mileage (km)
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