First time forum user, and I'm hoping someone can help. I have a 2006 Civic and over the recent month the gas mileage keeps getting worse and worse. I used to be able to get between 310-340 miles to a tank, and now it's only around 260-280. Keeps getting worse with each tank of gas. I have not changed my driving habits, and have been driving the same % city/highway that I always have. Recently had oil changed, tires rotated, air filter replaced. Just bought fuel injector cleaner (I haven't tried it yet because I'm waiting to get through the current tank of gas). I am well aware that with colder weather my mileage will decrease somewhat, but this is pretty dramatic. Open to any suggestions! Thanks!!!!

 

welcome to the forum. check tire pressure and bring it up to 36 psi, Is the car kept washed and polished? This helps a bit. Alighment good or done?

 

That's a big loss in fuel mileage,check your plugs and wires also.