I have been getting low MPG on my 2001 Honda Civic?

I purchased a 4door 2001 Honda Civic Lx about 3 months ago. Since then I noticed that I have been getting poor gas mileage. Right now its around 21-22 miles per gallon. Most of the driving has been done on the streets. I have been conscience of accelerating so I don't think that's an issue.

Recently I did some maintenance and for the last 45 days nothing has changed. I replaced the spark plugs, oil and oil filter, put in a new K&N air filter. I also put in a new cabin air filter. Although I rarely use the air conditioner.

I did not put in a new distributor cap, or spark plug wires because the 2001 Honda Civic doesn't have this. Instead Honda uses a different thing. I also did not replaced the fuel filter because it was under the back seat and I'm not sure how to do it (I have an idea).

In addition I checked the tire pressure. The only thing I can comment on that is that the front tires are one brand and it said to have the psi at 44 while the rear tires are another brand and said to have the psi at 35.

I also added Lucas Oil fuel treatment to see if that would help.

So my question is what can possibly be wrong with my car? The MPG should be around 30+ for street driving.

Any input or ideas would be helpful. Please be specific as to what to check and how to do it step by step.

Thank You.

Shane A2010-10-03T18:58:21Z

Favorite Answer

First, do not fill the tires to what they say on the side of the tires. That is the maximum pressure for the tire, not the pressure that the car should have. You can find out what the car tire pressure should be either on the glove box door, fuel door, or driver's door post. Now to find out your true gas mileage, fill the tank, then drive it on the highway, in non stop and go traffic for at least 200 miles, then refill the tank. Write down the mileage when you first filled it then when you fill it after your 200 mile trip. Divide the mileage by the amount of gas you had to put in the second time.
If your mileage is still low, this can be caused by a lot of things, cat converter could be getting clogged, oxygen sensors could be going out, engine being worn, etc. Without being able to do a good diagnostics on it, all we can do is guess.

merkl2016-10-04T17:59:30Z

2001 Honda Civic Mpg

Anonymous2016-03-14T13:44:47Z

Is your check engine light on? You may have a vacuum leak (vacuum pressure runs alot of little things and can trigger certain sensors that help an engine run better-my saturn had one and it ran like a dog till I replaced a simple O-ring. Are you sure your car doesn't have spark plug wires? Even if it doesn't have a distributor (its probaby a coil or pair of coil packs) it should still have plug wires. I would check the coil packs-sometimes they can start to corrode or rust from the bottom and when that happens and moisture gets in there it starts havoc. I would have your vacuum system checked for any leaks, and also check the coils and wires (which I'm sure you have) You may need to bite the bullet and take it to a dealership, although I would try a decent mechanic first.

Anonymous2010-10-03T22:17:19Z

yea, check the tire pressure, i keep mine at about 30-35 psi, i guess you should check for a leak in the tank? seems like if its a sudden problem, then something as sudden as a crack in the tank could do it. Or you could just be getting typical civic gas milage. I think if ur sitting in traffic or at red lights a lot, all that idling kills your gas milage.

Shift One2010-10-03T18:57:27Z

its because your driving in the city, that 30mpg is based off of highway driving, the more you stop and go the more gas your going to use.