maybe they didn't empty the oil reservoir fully before refilling?
actually, at Glenmarie, they kept checking the dip stick and then topping up so I'm pretty sure it'll need a bit more than 4L
adrwoon > yours is 2.4 so it should be different from our 2.0l.
I am very sure 4l is enough for 2.0l. By the way, we must remember any indication between middle to "max" on dipstick is actually enough. Not even necessary to touch "max" on the indicator. My previous ride I always make sure the oil does not touch the "max" as engine will feel heavy. Thats y i say 4l is more than enough for 2.0 sonata. Up to you guys. . .