I have an 05 Civic EX and the fuel mileage had dropped off. It was around 34 to 36 and it has fell to 28 to 31. I changed the plugs and airfilter with an K&N unit. The car has 46000 on it. Any ideas???

Thanks Mitch

 

Just search, there are about 5 billion threads on this already.

 

are you talking about highway miles or city? coz my 05 civic lx just clocks 28-29 city (dunno about highway yet)... well i know for one thing because of short frequent trips from home to office.