indynic

Hey, new here. I have a 2006 Civic Coupe LX 5 speed, 58k. I am experiencing a loss of MPG. I used to average 35-36 MPG and now I am suddenly averaging 30 mpg. The only thing that is different is the air filter. I put in a cheapy STP Filter. Does anyone have experience with a K&N on these cars? Or is the factory Honda filter the way to go?

Could this air filter be costing me 5 mpg's?

Honestly, nothing has been done to this car on a maintenance level except oil changes religously. Is there any maintenance that should be done i.e. spark plugs, o2 sensors, fuel filter, tranny fluid etc.

Any help would be greatly appreciated!

Thanks

gearbox

iTrader: (95)

factory filter is the way to go. K&N has very poor filtration. or if you dont mind the extra trouble, oiled foam filter by amsoil (if they make one for your car) is the best. has very good filtration and flow. needs to be cleaned and oiled every 6 months tho. but i doubt a new air filter would mess with gas mileage unless it was really dirty. at 58k, i would at least change the plugs. trans fluid is every 30k miles. maybe you just got a bad batch of gas?

Gunboy96

Did you find a solution to your problem? I have a 2007 Civic EX and I lost 7 MPG after routine Maintenance, oil Change, trans change, Tire Change.
I have changed the Oil and the Tires and the filter still no fix. Would an overfilled transmission be the problem

smoore08civic

I don't know if it would effect your mpg but it is not good to over fill the trans.

eao_Bytor

I have an 06 civic with 144,000 miles on it. I used to get 38-40 mpg all the time. It is now down to 35-36 mpg. I have tried several different air filters and none of them have any effect on mpg. I am chalking it up to fuel re-formulation. I would typically see a drop in mpg in winter months but never this bad. I don't know what the refineries are doing different, but I don't like it. Must be the oil they skimmed off the gulf of Mexico after the BP spill.

TRIZ

iTrader: (14)

Doubt it.

You probably did something to change your MPG, like changed tires, or inflation- any one of them off, alignment, lowered?? Break pads, or over adjusted parking break and it may be rubbing... are you running AC or defroster now- windows down.. or parked with the engine running?

If not, then your O2 sensors could be getting wacky readings. Did you change intake filter, or cabin filters? I always fill up at the exact same Chevron, or at least Chevrons in general- a good idea as Chevron/shell/76/texaco all have different forumlations which can cause the difference.

anhkhoi84

I got an 08 civic coupe ex and it has 93K miles on it already. Since I bought this car, I only fuel premium gas even though I don't have to. My MPG still the same so I think the gas has something to do with it.