Hi - I have a 2000 Civic LX 4 door I bought brand new. I have almost 163,000 miles on it. It still runs great and I have never had any problems. I've had tune ups done and change my oil regularly for the most part. I've never changed the timing belt (just trying to give as much info as possible.) Also it is an automatic.

From the time I bought it I was able to get about 330 miles per tank. This was the case until about mid 2004. Since then I'm lucky if I can get 240 miles per tank. The only thing that changed around that time is I moved to a place with a different climate.

Any ideas or help with improving my MPG would be very appreciative.

Thanks.

 

won't help with gas mileage but you really need to change your timing belt, like now... if you don't soon, gas mileage is going to be the least of your troubles

what do your tune-ups include?

try using seafoam (look in the DIY section)

 

Is the CEL ON? When was the last basic tune up done (plugs, wires, cap, rotor)?

You also might have a lazy O2 sensor.

 

if your weather is really cold now, then it will affect mpg. there is no way you will get the same mpg as you do in the warm summers.

i concur with trust that you definitely need to get that timing belt changed or else get ready to pour a lot of money to fix your car.

Also, have you changed your other fluids (coolant, brake fluid, ATF/MTF, etc); how are you brakes (maybe they are dragging); what kind of spark plugs are you using? People recommend NGKs here cheap but excellent for your car;

 

Thanks for the replies all. Let me try to get these questions answered.

I know what you mean about the timing belt. But a mechanic that I trust inspected it and told me it was in good shape and not to worry about it unless I'm racing. My tune-ups include plugs, wires, cap, rotor. And I'll look into the seafoam thing.

Right now I'm in a mild climate. I bought the car in Los Angeles. I moved to Portland for a couple of years and now I'm back home in Los Angeles. So cold weather is not currently a problem.

The CEL is not on. I figured that if my O2 sensor wasn't working right, the CEL would be on. I was also thinking maybe the fuel filter? I don't think I've ever changed it. The last tune-up was done about 30-40k miles ago.

I changed the coolant a long time ago (maybe at 50k) and I've changed the transmission fluid about 3 times. Other than that I've never ran low on anything else, but i'm sure it's probably a good idea to get them changed. I'm not sure what brand of spark plugs I have and the breakes are fine.

 

The fuel filter is definitely worth changing. it costs around $13, and may help some with gas mileage.

Let's put this in perspective.
Honda rates their timing belts at 105k miles, and you're at 163k miles. Based on my calculations, you drive about 20k miles a year.
Would you drink a glass of milk that expired 3 years ago?

 

FYI: A bad O2 sensor does not always throw a CEL code.

 

Thanks for the suggestions guys. A couple of questions.

1. Where is the fuel filter?
2. How can I check if the 02 sensor is bad or not?

 

Though it's not affecting your gas mileage, replacing the timing belt is a very urgent issue for your 163K-mile Civic. If the belt breaks or slips, the engine may be trashed.

The fuel filter is just to the right of the battery as you face the front of the car.

You would need a good scan tool to test the performance of the primary O2 sensor (see 96-00 Civic manual at link in my signature).

Also inspect the spark plugs, distributor cap, and rotor for wear and corrosion. Replace with OEM parts if necessary.

 

That is such a serious change in mpg that I would think you might have noticed some other degradation in performance if it were engine or fuel related. Might look to some really basic stuff like alignment. You could have toe in problems that result in no pulling but really impact mpg.