Up until two months ago my 2012 Holden Captiva 5 was getting 11L/100km, now it's getting a miserable 16.9L/100km. I haven't changed my driving habits and the car yard couldn't find problem.
It needs to go to a mechanic who can properly diagnose it. It sounds like it could be a sensor problem, which should show up on a diagnostic check.
Disclaimer: You acknowledge and agree that all answers are provided as a general guide only and should
not be relied upon as bespoke advice. Carsguide is not liable for the accuracy of any information
provided in the answers.