Hi all I'm having trouble with my Mazda tribute 2004 model , when I first got the car I was getting around 450-490 km out of a tank of fuel but now I'm lucky to get 330km can anyone recommend something , I have had it serviced on time always and tune up as well but nothing helps

 

Book it in for tune up. Get it scanned for fault codes. Get the O2 & Airfuel sensors inspected/monitored. Get the short term & long term fuel trims inspected/monitored.