Fuel consumption Chery Tiggo 8pro. from eastern cape to Gauteng.

I took chery tiggo 8 pro executive from east London to Johannesburg. Putting petrol was not fun on this thing. Initially AFC was 13.4l/100km,but it went down to 9.0l/100km when I got to Gauteng. I'm also gonna be sharing total cost of petrol coming back to Eastern Cape.