I have a 2016 Honda Civic 4
I have a 2016 Honda Civic 4-door Touring. I never got very good gas mileage from day one. However, immediately after my first recommended oil change there was a noticeable improvement in gas mileage. Maybe some Civics are being shipped with the wrong engine oil? It should be 0W-20. Where I live, it never gets really cold. I don't drive with heavy loads and I've always used the ECON button. I started out averaging 31.6 mpg combined for the first 6000 miles which included two 1000 mile road trips. I never really got above 35 mpg even on road trips of mostly highway driving. However, after the first oil change, I immediately noticed an improvement. I drove a similarly with a similar amount of road trips and got 34.1 mpg combined.