High Fuel Consumption, Low Top Speed: Passat TDI

Hello everyone, fellow mechanics!

"For the past week, I've been experiencing unusually high fuel consumption, and the maximum speed I can reach is only 190 km/h!"
The tire size is 215/55/R16. My Passat used to consume around 6.0 liters per 100 km on the highway at 120 km/h, but now it never goes below 7.5 liters. Driving in the city is terrible; it normally consumes 8.3-9.0 liters.
I find it very strange! Otherwise, it doesn't produce any smoke, not even a hint of it, even at 4000 RPM!
I did a logging run today, but unfortunately, I can't properly interpret the readings! Could someone take a look at it? I'm completely at a loss!