Why is my Kia Seltos consuming so much oil?

That’s a great question and suggests you shouldn’t take no for an answer in this case. Plenty of modern cars use a bit of oil (actually, all engines use some oil) thanks to the low-tension piston rings fitted to improve fuel economy. Swings and roundabouts. But 600ml of oil in 1000km is not something you can ignore.

Had the car always used this much oil, there’s a chance that this is 'normal' oil consumption. But the fact that the consumption has suddenly jumped up to the point where the engine ran out of oil makes me think that there might be a problem. Some oil consumption is normal, but it’s when the engine’s drinking habits change that you can have the beginning of a problem.

The fact Kia has admitted some engines had been fitted with poor quality piston rings, would make me think your car is one of the affected ones and should be fixed at Kia’s cost. I’d be curious to know what inspection the dealership conducted to assess your engine. One possibility would be to have the engine independently tested and assessed in terms of its cylinder compression and what’s called a leak-down test. This will give a much better idea of the condition of the engine’s internals and what’s needed.