Ok guys, I ran out of solutions, I really need your help
 

I purchased a 2009 Honda Accord I4 automatic just 6 months ago. I had a Civic before and I really loved it and decided to stay with Honda.

Ever since I got the car, I have been trying to maximize the range so to get an idea how much fuel it consumes. And tank after tank, I am going anywere between 18.6 to 19.4 MPG.

It has been bugging me since I got the car. I did some research online before making the purchase and everyone on the accord forum is getting 26+.

Although my driving is consist of mostly sub 5 mile trips in city, I expect with my very careful driving, at least I would archive the EPA which is 21 city.

But it seems no matter how I drive the car (I tried brisk acceleration too), the MPG doesn't vary much.

The breaks are not dragging I checked it and now I don't know what to do! The car slows down pretty fast in gear, but it does coast very far if I switch to neutrual and I pumped the tires up to 38PSI.

Although I am not financially pressured to save fuel, but I am bothered by the idea that there might be something wrong with the car.

What are the other things I can check for, please. Please list your ideas. Or ask for any extra info that may help you suggest ideas. Thanks a ton.

Is the thermostat stuck open? Do you have the A/C on, and/or the defroster on all the time? Do you have a ScanGauge or UltraGauge, and have you gone on any longer drives? Under 5 miles will almost never get the engine warmed up enough.

With less than 5 mile trips you will be hard pressed to get good milage. For your driving technique, if you aren't already work on letting the car coast as much as possible before coming to a stop. You don't want to power the engine right up to a stop. With some practice you will learn when to put it in neutral or let out on the gas. Learn to take turns "a little fast" (but still safely) when you don't have to stop to keep up your momentum. As far as mods go you should consider an engine heater if you park in a place that you would have access to power like a garage. Most engines add extra fuel until the engine heats up, so even when you are coasting in neutral a cold engine will use more fuel than a warm one. I experience this every day on my commute.

If you don't put a lot of miles on your car you should be changing the oil based on time, or a reduced milage figure. Warmed up highway miles are a lot easier on a car than cold city miles.

What kind of automatic tranny it has? Has its oil ever been changed? Block heater and grille block would help with short trip MPG especially in winter..

Like Neil said, if you don't already, definitely need to get an SG/UG. That will help you determine best driving practices, even for a 5 mile drive. I would also do all maintenance work you can. Check the oil (level and "freshness"), transmission oil (level and "freshness"), battery voltage level, you said you checked the brakes, but what about the tire threads?, also 38psi might not be the best pressure for you (a SG/UG would help you determine this).

After maintenance, you can do some MODs. If you are only doing 5 mile trips, I would try to seal up the engine bay as much as possible, so the engine gets to operating temp further. So grill block, belly pan, etc.... Some other aerodynamic mods would be helpful (full belly pan, rear diffuser, kammback, etc.).

As Neil mention, if you run the defroster all the time, you might be running a/c without even knowing it. You'll have to take out the a/c belt, a/c fuse or cut the a/c wire from the defroster.

What about weight? Are you carrying a lot of stuff or is the car basically empty?

Hope this helps! I'll probably come up with more ideas as soon as I press the submit button! :)

I agree with aardvarcus. Under 5 miles is not much time to warm up the car and start regaining the penalty of a cold engine, especially in winter. A block heater will help negate this penalty and that is probably where I'd start.

Thanks for all the replies guys, I will try to answer some of your questions so you guys can have a better idea on how to help me.

I park the car in a underground garage which is I am guessing around 35-40F. I don't run the defroster all the time but I do only use Defroster + Leg setting. Which means when I want to warm up the car, not necessarily to defrost the windshield, I turn on the defroster + leg. Does defroster uses more energy compare to just regular hot air (like the leg only, or upper body etc).

I have recently changed the engine oil to synthetic and changed transmission fluid.

The threads on the tires are pretty worn out, I have about 3/16in left from the minimum thread rib (this car has 35k miles on it).

I try my best to coast the car but you know in cities, other drivers are always up your a**.

I am currently only trying to find out first of all, does this car have a problem. IF NOT, what can I do and how much I can improve the mileage with just driving techniques.

I don't want to mod the car because it would skew the result, since this car is a lease and I got a good deal on it, I can afford to sell it at a reaonable lost and change to a new car.

Very similar thread here, from another fella in Vancouver. The responses are applicable to your situation.

I am not sure if this is an honest mix up, or you are making fun of me. But that fella is me.

As you can see I have been on this issue for a while and been looking at every possible cause.

As far as coasting goes, as a result of that thread, I conclude that there is nothing wrong with my car's coasting, at least in Neutral.

Which then leads to this thread because I have already exhuasted possible causes for obvioius mechanical faults.

Check spark plugs and lambda sensor. I know probably for such short commutes engine will stay in a open loop but I think that Accord has heated lambda. You may check inlet manifold for leaks, and exhaust as well.
If I'll think of something more I'll post.