How much oil is in the tank?

Hello, who is knowledgeable about oil tanks. The display shows 88cm (I would say, see picture 1) filling height. The tank holds a total of 4600 liters (see picture 2). Can I now assume that the tank is full at 150cm (end of the scale), meaning it holds 4600 liters then? Then it would be 58.66% full at 88cm, which would correspond to 2698 liters. Thanks for your expert advice

Did you even read the question?

Did you even read the question?

You answered your own question. The calculation is correct if you neglect the rounding at the bottom of the tank.

Is a folding rule so heavy that you can't just hold it into the filling hole and measure yourself?

Soroka means that you should measure the fill levels yourself. It might be that the display is stuck, or the tank is 1.60m high (because in my opinion that's where the scale ends). But nobody in this forum can answer that for you. Instead, you have to take a folding rule in your hand and measure.

So on the tank you can't see any curvature from the outside, but could there still be one inside? Is there often an inner liner or something like that inside? I just can't look into the thick metal box.

That was also part of my question, to what extent you can rely on this display scale. The speedometer on some cars goes up to 250 km/h even though the car doesn't drive that fast.
I have now measured, the external dimensions are 150 cm in height, so presumably there won't be an inner liner or anything like that inside, right? If such a thing even exists in tanks.
I have no idea about this stuff, so these might be dumb questions for you.

Have you read #2? Folding rule and measuring again.

Upon arrival, first measure LxWxH with the still clean folding rule and check whether the remaining details of the total fill volume roughly match.

If it is quite symmetrical and octagonal and dodecagonal, it shouldn't be that difficult. If it is even barrel-shaped, knowledge about Pi helps a bit.