u/DasNoiceXD

I own a 2011 zen estilo, k series (3 cyl engine) and since past couple of years i've been getting a very bad fuel economy. Around 8 kmpl to be precise. this month i have been working on all stuff that can cause this, replaced airfilter, sparkplug, fuel injector, fuel filter and o2 sensor all have been changed. My throttlebody was messy so cleaned it, the MAF sensor which is a temp sensor is also cleaned. Everything that could have been cleaned or replaced is REPLACED and still not a single digit difference in the fuel economy. Other people get fuel economy of around16 kmpl in city and 20 kmpl on highway while mine gives 8 kmpl only, What could be the problem?