Should you check the oil level in the engine in an agricultural tractor immediately after the engine immobilisation?

In the photo you can see a part of a tractor engine with hoses and a large red oil filler cap. You do not check the oil level immediately after the engine has been stopped, but after waiting for the period stated by the manufacturer in the owner's manual - answer B.

While the engine is running, oil circulates through the whole lubrication system: it is in the channels, on the cylinder walls, in the cylinder head and in the filter. After the engine is switched off, the oil needs a moment to flow down into the oil sump - a measurement taken immediately will show a level that is too low, and you may add oil unnecessarily, overfilling the engine. How long to wait depends on the engine, and the manufacturer gives this in the owner's manual; usually it is a few minutes. A measurement immediately (answer A) is therefore wrong, and waiting an hour "always" (answer C) is an exaggeration that neither the rules nor manufacturers require. Also make sure the ground is even and level - on a slope the reading will be false anyway.

Legal basis: Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)