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.

What do you look for on spark plug and O2 sensor? There is no Check Engine Light, so beside to see if it is visually dirty, how do I know if they are affect anything?

This car is pretty new, 2009, do you think it is possible to have manifold leak and how do I even go about checking it?

My apologies Jay; I was sneaking in a forum visit during a boring meeting at work and didn't pay enough attention. I just knew the problem sounded familiar.

Hey Bud, I'm pretty sure when you have it on defrost the AC compressor runs to condense moisture inside the cabin and defog the window during rainy days. I think it's supposed to know when it is below 35-40°F (2-5°C..eh) and not run the AC, but I've always been suspect of that. So, be sure you're not running defrost unless you gotta. And don't recirc the air either, this will cause your windows to fog up, recirc only on crazy hot days or when you're going by a pig farm er sumthin. I see people drive by all the time all fogged up and would bet real money they're recircing the air.

I could be wrong about the AC shutting off at what temp or if it even does. But I'm certain the AC comes on when at 50°F & above when you have it on defrost.

Did you have the civic with your current commute? Mpg w/ the civic?

With my old commute i did alot of 40-45 mpg tanks. I had a tank under 20mpg this winter, but I have a short commute now and don't think there's anything wrong with the car.

Thanks for all the replies guys. Can you please, when you suggest what to check, include what I should look for.

How do I check a O2 sensor? I can take it out and then what? I am sure it won't be shiny but how do I know if it is affecting my mileage.

Or spark plugs, what do I even look for?

I know the newer ATX are better but you're still slipping until lockup in the final gear. 4 cyl are most affected on a % mpg basis. Don't compare MTX and ATX fuel economy.

Just to illustrate my comment on a cold engine using more gas, this morning I did a few tests. There are some good places for me to Pulse and Glide, so while my car was in neutral idling, I checked the temperatures and fuel consumption. There were three cases:
Car was cold, only running about a minute. Engine was at 32 F and Intake 32 F. Car consumed 0.70 – 0.75 gallons per hour coasting in neutral.
Car was partially heated up, running about 8 minutes. Engine was at 160 F and Intake 36 F. Car consumed 0.27 – 0.30 gallons per hour coasting in neutral.
Car was fully heated up, running about 30 minutes. Engine was at 185 F and Intake 68 F. Car consumed 0.24 – 0.25 gallons per hour coasting in neutral.

Here is the best test that I can think of to check that your car is functioning properly. Only takes an hour and costs about $10. Go to an interstate or highway where you can drive 60-70 mph. Fill up your car at a fuel pump until it clicks off 3 times. Drive for 30 minutes on the highway in one direction, turn around, and drive back. Try to be “nice” to the car, moderate acceleration using cruise control and going with the flow of traffic. Don’t hyper mile, just drive nice. Come back to the exact same fuel pump (important) and fill the car to the same level (clicks off three times). Compute your MPG. This won’t be extremely accurate, but should be close. Compare this number to the EPA highway rating on your car. If your MPG on this roughly hour highway only trip doesn’t meet or exceed the EPA highway figure, I would bet there is something wrong with your car.

Is your idle to high? It should be 700-800.

Loosen the kick down cable on the trans, it should stay in high gear a little longer.

did you get car from a used car dealer, I've seen some real stupid rigging to make cars appear sellable. Maybe it would not idle and they set it real rich

does it have stock air filter setup or a hot rod cool air intake?


What rpm does it shift into 4th gear?

If you got muscles, take power steering belt off.

vacuum leaks will fake out sensors, fill a spray bottle with water, spray vac hoses, listen for engine stumble.

Make sure clamps on intake hoses are tight to throttle body, and its not cracked and air filter hosing is clamped good...SC

There is one solution to getting great mileage when all your trips are under 5 miles.

It's called a bicycle.

No vehicle out there will get good mileage when it is running in closed loop the majority of the time.

You can check if o2 sensor is working properly with any OBDII scan tool or ScanGauge, UltraGauge etc. You should see Lambda numbers which should vary in a pretty fast rate. If the changes are slow or there are none your o2 sensor is just a piece of junk.
Regarding spark plugs you should check the gap between electrodes. It should be in a factory range.

I've seen leaks in almost or brand new cars either so the car age is not a factor here. Sometimes is just a bend hose, loosen screw or many other small things that can affect air fuel ratio.

You can do one more test. Let your engine to idle for a while just to warm up a bit and then just smell the exhaust gases. You shouldn't smell unburned fuel. If you feel that or you see any smoke like fumes there's something wrong. Then you should take your car to any service for exhaust gasses analysis. It can tell many many things of your car's engine to see what is coming out of the exhaust.

:thumbup::thumbup::thumbup::thumbup: I agree! ;-)

But I think you've meant open loop :)

Yeah, that's it, open loop.

I have a 12+ mile commute to work. In the nicer weather, I sometimes bike commute. If I had a <5 mile commute, I'd do it a hell of a lot more.

I have ~4.5 mile commute to work and the same back home. And I'm riding a bicycle (regardless weather in -25C too) I can't imagine such short commute's FE in -25C

-25C? What's that in real degrees? :)

A bit below zero, if my math is right. That's awesome.

If I had that short a ride, I'd certainly be less of a weather wussy.

It's -13F

For practical reasons I can not ride a bike. If you must know, I drive my wife to work as well that's just on the other side of the block. So even if I bike, she will drive.

We live in a small apartment so there is no room to even park 1 bike, let alone 2.

And it is rainy in Vancouver during winter, nor does the road here have bike lanes.

Saving money on fuel is onething, driving a car that has defect is another. I am merely trying to determine if there is a problem with the car.

With respect, I think you're on a wild goose chase.

I think the odds are that you're just not going to get the rated city mileage in hilly Vancouver urban driving from a cold start over that short a distance. It's not the car. It's the way the car is being used.

Someone else asked a good question: were you able to get the rated city mileage in your previous vehicle on the exact same commute? Did you track it?

I'm new here, but would like to put in my 2 cents worth. I also have a short commute of under 5 miles, but I drive a 04 explorer with 4wd and 4.0 liter engine and will average about 16 in the winter. Thank goodness winter in MN is almost over and I can start biking to work. It looks like you bought it last fall which means it has only seen a winter blend of gas since you have owned it. I would like to know what the summer blend will give you. I have been tracking my mileage on fuelly for the last couple of years and have paid close attention to what brand of gas I use. So I know in my area which one will give me the best mileage, just something you might want to think about. On this web site (Fuelly) you can also compare what other people are getting on different models of cars. So I did a comparison for a car like yours and someone from the southern US who drives mainly in the city is currently getting low 20's for this time of year. So considering it's a lot warmer there and probably a different blend of gas you may not be that far off for your car.

Hello guys, I would like give everyone an update. I had a road trip this weekend so I took this opportunity to test my 2009 accord's highway fuel consumption.

I drove a total of 260km back and forth, of which about 200km are regular highway that I maintained 90-105 km/h; 60 of them are city/suburb driving ranging from 50-80km/h.

I have 3 passengers and some snowboard equipment. I guessed about 580lb of human and 80lb of cargo.

I ran AC for about half hour and had fan on low the whole time. Tire pressure are 40psi and I didn't use much cruise control.

The result is 7.8L/100km or 30mpg, which is exactly what the EPA rating is.

So... I not sure how EPA highway rating is obtained, but I think that it can only get better if I drove pure highway and only have 1 passenger?

All in all, I now incline to think that there is nothing wrong with the car.

One unrelated observation though, I cleaned my rims about 2 months ago, and now my rear wheels are coated with break dust, but I can still see metal on the front wheels.

Definitely. Sounds to me like you've got your answer to this problem.

It's unusual to see more brake dust on the rear than the front. But maybe it's not brake dust at all ... it could just be road grime. The rears would get more of that than the front on a long trip especially if the roads were wet and dirty.