You need to determine where the problem is: You or the vehicle, or both.
Vehicle: Is tire pressure at recommended level? Wheel alignment correct? Brakes not dragging?
You: On trips do you stick to the speed limits and use cruise control? Do you brake at the last minute or do you anticipate the need to slow down by coasting? Do you accelerate moderately or rapidly? Are you on and off the accelerator or have a steady pace? Driving with moderation in everything and a steady gas pedal is the ticket to good fuel economy.
Your driving habits are the biggest determinant of your fuel consumption.
Edit: Short trips/city driving in cold weather kills fuel economy. Hilly terrain is just as bad and the combo is terrible.
Last edited by modelamac; 01-30-2019 at 10:14 AM.