Well, In North America we only have the 1.8l engine to go by but the same things can be checked. Check air filter, spark plugs, Has the oil been changed, is there a brake pad or drum slightly sticking causing excess drag. What fuel are you using has there been a change. I grew up in a foreign country and know that not all fuel is the same, even here in North America there is a difference in fuel. Have you taken your car to a dealer to check out?. 2014 should still have warranty on it. Speed also plays a roll, how fast do you drive, do you hammer down on the accelerator when the light turns green?. Many things can play a factor, if your habits have not changed than maybe a trip to the dlr to have your car checked is needed.