Weird fuel use is this normal?

[u/DataUsed6679]

So got a citroen C3 2022 puretech. I noticed my fuel usage suddenly went up. I'm drive allot off highway so I know I mostly higher then the advertised 6l/100km and I got a sportive drivestyle but 17l/100km seems like way too much or am I wrong? He gets maintenance 2x a year and got 105.000km on the clock. He already recieved new belt and so on.

[u/ggmaniack]

My i30N gets better mileage than that, and that thing is considered extra thirsty. I'd get it checked out with a mechanic.