My 00' accord sedan 4cyl 2.3l is giving me terrible mileage. I am getting around ~284 miles for a full rank of gas. I use to be able to get high 300s. With summer around the corner its only going to get worse with the A/C on! I am suspecting it could be the fuel filter but I am not certain. I would love to know what else it can be? But it may not be the fuel filter because my car can go up to speeds around 105-110mph with no signs of struggling at all. Any advice would be great!

I use the cheapest gas rating if that matters from QT(QuikTrip) if that matters.

My timing belt, and water pumps has been rep[aced, didnt replace the plugs(dealer said they were lifetime platinum plugs). Oil Change is done around 3-4k miles never more than that. I use the red bottle of Valvoline using 10w-30 in summer and 5w-20 in the winter, FRAM high mileage Filters.

my current mileage is 121k.

* I am not driving 100+ all the time :p so dont tell me to slow down LOL I was just making a point about the fuel filter may very well be fine.

That's an incredible drop assuming you are mostly taking the same route and driving the same. There are lots of little things like a filthy air filter, low tire air press, etc. that could lower mpg's, but those wouldn't take your miles/tank from high 300's to 284.

On the lifetime plugs your dealer told you about...Honda recommends changing the plugs at 105K (if memory serves). Assuming they have never been changed, it wouldn't hurt to change your plugs, wires, cap + rotor.

Maybe you should calculate mpg's using your trip odo vs. just looking at how many miles before E? What percentage city/hwy do you drive? Is your CEL on?

The plugs should be replaced at 105k with NGK or Denso platinums. Best deal on those can be found at your auto parts store. Sounds like your right on track with everything else you mentioned.

Slow down.... JK.
It wouldn't hurt to replace the fuel filter tho....:wave:

Since this is a honda forum, can I ask the ones with the same gen model as my accord, What kind of mileage are you getting on a fulltank?

MegaloRSEX:

IMO, the OEM NGK/Denso plugs really should be changed at Honda's specified (105K) mileage interval. While they are premium, platinum-style plugs, they don't last forever, either.

Other items for you to attend: Air filter, tire pressure/balance, and wheel alignment.

And for the record, I consider Fram filters GARBAGE.

Since this is a honda forum, can I ask the ones with the same gen model as my accord, What kind of mileage are you getting on a fulltank?

99 Honda Accord V6 Coupe 109,875 miles.

I've calculated this a few times now.

City - 18.29 MPG
Highway - 24.5 MPG

Since this is a honda forum, can I ask the ones with the same gen model as my accord, What kind of mileage are you getting on a fulltank?

With 50/50 city/hwy and a light foot I get 28-29 mpg (2.3L/auto).

2.3L auto 117k, about 30/70 city/hwy 25/26 mpg.

2000 SE 2.3 auto 110k original plugs, wires, etc 24 city - 32 highway

To All:

I haven't done much highway driving on my '02, so the jury is still out on that point. :dunno:

Around town? With my light foot, I'm averaging 19-20 mpg, per the advertised CAFE rating. I use only "Regular" fuel. (READ, I buy the CHEAPEST gas I can find!) :D

From what I've been told, the 6th-Gen V6 cars will typically have an overall average of around 24-25 mpg. The I4 cars, especially those with five-speed trannies, will typically fare in the 28-29 mpg range. :)

We are assuming, of course, the car is in a reasonable ("ideal") state of mechanical condition.

My trusty '86 averages 24-26 mpg, in town. (It used to be 27-29, before our ingenious city planners added 5,000 more damned traffic lights! I suppose they love for everyone to WASTE gas at every intersection!) On the highway, it gets around 35-36 mpg, cruise contol engaged, at a (relatively) constant 65 mph, A/C off. (Best ever? 36.46 mpg.) WHY do I know this? As I have the past sixteen (16) years, I check the fuel economy every time I fill it up. :thmsup: :yes:

I am still baffled what the problem could be. Car is generally dealer maintained for big problems or tuneups. Only thing I do myself is change filters. I was thinking maybe my stereo is producing a lot of weight but when I think back this system now is about 50% lighter since I am using 1/2" birch ply instead if 3/4" mdf and considerably less wood now.

My rims and tires might be another factor. Could it possibly be the new ethanol additive that is in the petrol now days?

I drive mainly city 5 days a week about a 1hr drive round trip per day. weekends I do more highway driving average 2-3hrs round trip.

What is a CEL? Is that cruise control? if so, no, roads I travel on bend a bit on the country road.

Depending on how heavy my foot is, I get between 400-450 miles per tank. Of course a manual does wonders for mpg, lol.

I drive mainly city 5 days a week about a 1hr drive round trip per day. weekends I do more highway driving average 2-3hrs round trip.

What is a CEL? Is that cruise control? if so, no, roads I travel on bend a bit on the country road.

Your heavier wheels + sound system + increased ethanol % would contribute, but if you're getting <17mpg (284/17) out of a 6thGen 4cyl you've got bigger issues...unless your city driving is seriously congested.

CEL = Check Engine Light. Maybe bring it to Autozone to let them do a free CEL scan?

Yea I am stuck in traffic every morning at 7 am.

(cough, cough) spark plugs (cough, cough)

also: www.toptiergas.com

99 Honda Accord V6 Coupe 109,875 miles.

I've calculated this a few times now.

City - 18.29 MPG
Highway - 24.5 MPG
Wowo yours is low mpg for a 6th gen too. On highway you should be getting 30-31mpg. My 98 Prelude Type SH that had every engine mod plus vtec controller got 29-30mpg on highway or 330 miles to a full tank. My point is the F22 should get a decent number (2-4mpg) better than a twin cam H22. I'd def look at what parts you need and do a full tune-up (plugs, filters, etc). I'd even run fuel treatment (sea foam etc) too with a tank of 93 octane it you dont wanna change the fuel flter right now (which you should) and see how than changes things (or doesn't). But i wouldn't do the fuel treatment/93 gas until you go on a good ride on the freeway so the engine is at its most effecient rpm range and stays at a constant. But city situations are different from day to dat so measuring off city mpg isn't reliable. Interstate travel is usually more reliable with recording your mpg.

One thing i think everyone should do is take your car on the freeway once every month or two. Notice how cars with mostly highway miles tend to last longer. My prelude was purchased the year i went to college in 98 brand new. I still Worked for an airline in Wilmington. If the flights were full and i could not get a seat, I'd drive 7hrs home but i digress. I sold my car in 02 with 160,000 miles. Did everything asked to be done when it was supposed to be. My car today is still running strong today with almost 200,000 miles. Highway miles are the engines happy rpm range. So im now rambling so i'll STOP...LOL.

Okay I changed the plugs today, looked like it needed it bad. Hadnt been replaced in 9years. lets see if it helps some atleast. I used NGK Plats

http://i135.photobucket.com/albums/q151/Megalomaniac1989/Car_Detail/IMG_6757.jpg

http://i135.photobucket.com/albums/q151/Megalomaniac1989/Car_Detail/IMG_6759.jpg

http://i135.photobucket.com/albums/q151/Megalomaniac1989/Car_Detail/IMG_6753.jpg

MegaloRESX:

WISE move, I'd say. NGK Platinum plugs (for my V6) run about $16 a pop. But well worth it. From what I've seen and personally experienced, Honda's perform better with NGK or Denso plugs. I use only NGK! :thmsup: :yes:

I got these Plats for $3 each from Autozone. They were selling the NGK PLat-Laser for $10 each. I didnt want to shell out that much cheddar in times like these.

I got these Plats for $3 each from Autozone. They were selling the NGK PLat-Laser for $10 each. I didnt want to shell out that much cheddar in times like these.

How's she running now? Hopefully you can notice a difference in performance.

I havent driven the car much last night since I switched the plug, I drove it around the block thats it. I think the ECU needs to adjust to the new plugs not sure. I will post updates!

I havent driven the car much last night since I switched the plug, I drove it around the block thats it. I think the ECU needs to adjust to the new plugs not sure. I will post updates!

Did you reset the ECU? It will of course adjust itself, but resetting it never hurts. :thmsup:

How do I reset the ECU? If If I dont, how long does it take to adjust itself?

How do I reset the ECU? If If I dont, how long does it take to adjust itself?

Take the negative cable off of your battery for at least 1 minute. Put it back on. I'm not certain how long it takes if not reset.

I am starting to write a log on my fillups in a little composition book. Today I filled up the tank after 294 miles, it was showing it was on E, reserve light did not come on yet. I pumped 13.xxx gallons into the car. I calculated roughly 21mpg and on this tank it was mainly all highway driving. I will continue to monitor this for about a month at least and see if its my driving habits.

I calculated roughly 21mpg and on this tank it was mainly all highway driving.

Yikes. With combined city/hwy I get 24-26mpg's, all hwy is high 27's to low 29's depending on the wind. I get to the speed limit pretty quick in town, but I shift around 3k rpm's.

I am starting to write a log on my fillups in a little composition book. Today I filled up the tank after 294 miles, it was showing it was on E, reserve light did not come on yet. I pumped 13.xxx gallons into the car. I calculated roughly 21mpg and on this tank it was mainly all highway driving. I will continue to monitor this for about a month at least and see if its my driving habits.

Does your reserve light ever come on? I'm asking b/c mine comes on well before I hit E. Also when I run mine down to actually being on the E line I can only put <2 gallons in, while you say you're putting in ~4?

294 miles into 13 gallons came out to just under 23mpg. was that tank of gas mixed driving? what percent hw/cty? This all should be in the equation. this is why i contineu to say go out on the highway.. clean al the "gunk" out your motor and get a better mpg number.

294 miles into 13 gallons came out to just under 23mpg. was that tank of gas mixed driving? what percent hw/cty? This all should be in the equation. this is why i contineu to say go out on the highway.. clean al the "gunk" out your motor and get a better mpg number.

That tank was majority highway like 95%, that last 5% was just city driving to get to the highway. I have been driving on the highway a lot lately since school has been out, been working driving around to different hotels for video shoots around Dallas.

You think Seasfoam should be an option?

That tank was majority highway like 95%, that last 5% was just city driving to get to the highway. I have been driving on the highway a lot lately since school has been out, been working driving around to different hotels for video shoots around Dallas.

You think Seasfoam should be an option?
Yes it would help a lot. Add into throttle body and gas tank. Sea foam cant hurt. 21-23mpg on the freeway with an F22/23 isnt that great so yes do that and maybe even a tank of 93 octane. The detergents will help clean the fuel system in return giving you a better more effecient combustion. Btw. how is your tire psi? do you have them at 32psi < 40psi? Also a new air filter/ k&n drop-in wil help.

With <23 mpg hwy I still think you have something major going on that a dealer/shop should be able to figure out. I haven't done this in a couple of years, but the last few times I took my 02 on mostly interstate trips I got 32-33 mpg with cruise set at 85 mph.

To answer the earlier question I accidentally overlooked,My reserve light did not come on. The gas line was right at the E not below the E.

Something bust be seriously wrong. I am the only owner of the car, and car has been dealer maintained on all major work.

I run low profile tires, I keep them filled around the 42psi range. I forgot the size of tires I will have to look. But they aren't thin rubberbands like I've seen on some cars.

21.74 mpg I calculated today, and it hit the reserve too.

http://i135.photobucket.com/albums/q151/Megalomaniac1989/May_26th_2009_Crown_XLS_202_Amp/IMG_6799.jpg

Okay today I did my oil change, I am using Valvoline High Mileage synth blend 5w 30(I know the Mobile1 is on sale at walmart but I already had this in my storeroom), still using fram filters, I also went ahead and changed my air filter under the hood today. Added air to the tires too. I hope all this helps. We shall see!

I never see more than 320 in a city highway tank of gas.

I have a 99 EX i4 AT with 153k miles almost.

I get about 23mpg mixed which is right on with revised EPA estimates, this isn't the most fuel efficient car. I say its mainly due to all the high revving the engine is always having to do, and it doesn't help that the transmission seems to be geared to go to 3k rpms before a shift at the least, it doesn't take much effort to make it take a gear all the way to 4k rpms. So you really have to try hard to keep revs low, if you even can in the AT form of this car. Mine always goes for 3250 rpm shifts in city driving, and if I don't push the pedal enough it just holds it in that gear and won't change. Funky setup but I've driven my best friend's 00 Accord and hers is the same way.

http://www.fueleconomy.gov/feg/calculatorCompareSideBySidePopUp.jsp?column=1&id=15103

Some of these may have been asked, I'm asking anyways.

What kind of shape are your tires in?

What is the PSI in your tires? I keep mine at 35.

Air filter?

If you just recently changed your rims, your odometer is off and not recording all the miles you are traveling. Bigger wheel = less miles on the odo, smaller wheel = more on the odo.


Don't know how heavy those rims are, I would compare if you recently put them on. I assume less, but cheap rims can be heavier and I don't know what kind they are.

Just because you're on the highway doesn't mean gas mileage will be good. If you're passing cars a lot, the engine revs up more which uses more gas, anything over 3k rpms on the highway you will see a decline in the gas mileage. Hills are also culprit. Highways also have traffic and congestion where you might have to slow down and re-accelerate, remember that.

putting your foot on and off the gas over and over again on the highway also doesn't do good, esp if you're the type to somewhat jab the pedal when you get back on it on the freeway.

My car gets poor gas mileage when I try to accelerate slow and easy. I've found just driving normally has resulted in the best performance. Any sort of idling is also a major mpg killer.

Just some points to consider.

To All:

There are two (2) P/Ns for OEM Honda engine oil filters. 15400-PLM-A01 is made by FilTech, Toyo Roki (and possibly some other vendor, but I don't recall). 15400-PLM-A02 is made by Fram or Honeywell.

My dealer presently sells only the "A02," but I suspect that the "A01" may be a better filter. However, as frequent as I perform oil service, it probably won't matter which version I use. :dunno:

I've owned my trusty '86 exactly 16 (sixteen) years, as of the 22nd of this month. From direct, firsthand experience, I have noticed a slight increase in MPG after my conversion to fully-synthetic oil in the engine and tranny. However, my basic motive didn't involve increasing fuel economy. NO, only enhancing (overall) performance and protection.

The fuel economy "equation" involves at least five (5) variables: Condition of tires and pressure settings; condition of steering/suspension components (i.e., wheel alignment, struts); condition of brakes; condition of drivetrain (engine/transmission/axles/wheel bearings); driving patterns/techniques (city vs. highway, aggressive vs. conservative).

Just for aggravation, I'll toss in two (2) more variables: Condition of (your particular) road surfaces and (your particular) climate considerations. New York, New Jersey, and Pennsylvania notoriously have potholes big enough to swallow an Elephant. Driving in frigid Alaskan cold vs. blistering Arizona heat are two (2) entirely different situations.

My salient point: YOUR particular machine must be custom-tailored to fit YOUR particular driving circumstances, to achieve maximum efficiency, whatever that so happens to involve. The "One Method Fits All" approach is an exercise in absolute futility.

Some of these may have been asked, I'm asking anyways.

What kind of shape are your tires in?

just bought new tires last summer


What is the PSI in your tires? I keep mine at 35.

45ish psi


Air filter?
see my last post, just changed it few days ago



If you just recently changed your rims, your odometer is off and not recording all the miles you are traveling. Bigger wheel = less miles on the odo, smaller wheel = more on the odo.

That is not true, The bigger the rim get the smaller your tires get, less meaty, to compensate for the full diameter of wheel. Odometer is not off, guys at NTB can verify.



Don't know how heavy those rims are, I would compare if you recently put them on. I assume less, but cheap rims can be heavier and I don't know what kind they are.

They are heavy yes, but that does not explain why all of a sudden this year the mileage went to hell.


Just because you're on the highway doesn't mean gas mileage will be good. If you're passing cars a lot, the engine revs up more which uses more gas, anything over 3k rpms on the highway you will see a decline in the gas mileage. Hills are also culprit. Highways also have traffic and congestion where you might have to slow down and re-accelerate, remember that.

putting your foot on and off the gas over and over again on the highway also doesn't do good, esp if you're the type to somewhat jab the pedal when you get back on it on the freeway.

My car gets poor gas mileage when I try to accelerate slow and easy. I've found just driving normally has resulted in the best performance. Any sort of idling is also a major mpg killer.

Just some points to consider.

I understand that. But from reading around on this forum and other forums, this kind of mileage from an stock(under the hood at least) Accord is completely unacceptable lead foot or no lead foot.

To All:


Just for aggravation, I'll toss in two (2) more variables: Condition of (your particular) road surfaces and (your particular) climate considerations. New York, New Jersey, and Pennsylvania notoriously have potholes big enough to swallow an Elephant. Driving in frigid Alaskan cold vs. blistering Arizona heat are two (2) entirely different situations.
.



Not many potholes in TX. Heat is around 103 in the summer, but in 80s in spring/fall. 50s-60s in winter.

Okay today I did my oil change, I am using Valvoline High Mileage synth blend 5w 30(I know the Mobile1 is on sale at walmart but I already had this in my storeroom), still using fram filters, I also went ahead and changed my air filter under the hood today. Added air to the tires too. I hope all this helps. We shall see!

Good choice on the oil. Isn't that oil called Max-Life? I stay away from fram oil filters...havn't heard a good thing about them. Fram air filters are excellent.

Not sure if it was brought up before since I first read this thread awhile ago. Maybe an alignment may make a difference or at least have it checked.

I got these Plats for $3 each from Autozone. They were selling the NGK PLat-Laser for $10 each. I didnt want to shell out that much cheddar in times like these.

Expect only 30K out of those plug's. If you want 100K you'll need to use the plugs specified in the manual (usually cost about ~$10-15 each). Also, cap/rotter and the wires (known as a tune up) need to be replaced too. Buy Honda OEM parts, or high end after market, or you'll be hear again, in less than 30K miles...

With <23 mpg hwy I still think you have something major going on that a dealer/shop should be able to figure out. I haven't done this in a couple of years, but the last few times I took my 02 on mostly interstate trips I got 32-33 mpg with cruise set at 85 mph.

I agree, something dose not make sense? I have 4-cylinder (F23-A4) with an Automatic, 205-65-15 tires, and junk-in-my-trunk, and I get (MPG City/Highway):
Lead foot: 21/28.
Normally: 23/29.

A/C on AND winter gas (subtract up to 1-3 MPG):
Lead foot: 21/26.
Normally: 22/27.

Worst ever: 19/25.
My Best ever: 25 City/ 34 Highway?

My suggestions:
Check tire pressure, minimum is whats on the door sticker (30 PSI). I use 36 PSI Cold.
Add bottle of FI cleaner, Red line SL-1.
Do a full tune up (inc PVC. Use Honda parts).
Get a front end alignment.
Check that the brakes are not dragging.
Change ATF (use Z1, assuming automatic transmission).
Change oil make sure your using the proper oil, 5W-20, Fuel conserving...
Change your brand of gas used.

Before I was changing my own oil, I was going to, "Oil Can Henry." They was substituting what ever oil they had, 10W-30, 5W-30, etc. Despite me telling them to use 5W-20. I lost 1-2 MPG's...

What size tires and rims do you have?
IS the car lowered?
Other mod's to car?

Take the negative cable off of your battery for at least 1 minute. Put it back on. I'm not certain how long it takes if not reset.

Lifting the Battery terminal will make it relearn but not reset persay.
Disconnect fuse 13 "battery backup," for 2-3 minutes, then disconnect the battery...

OK. I reread your post..

You stated your:
1) Using 5W-30, Your car needs 5W-20, "Fuel Conserving."
2) 45 PSI is likely too high. If the side of the tire said 45 PSI, that Maximum. I would not go over 40 PSI.

Your Fuel economy problem, may be an accumulation of problems:
Maintenance (update you cars service).
Use the proper oil (5w-20).
Wide or bigger tires can effect fuel economy.
Fuel used? I found that I repeatably got poorer fuel economy using CostCo Gas (temporarily change to Chevron gas for several tank fulls, see it this has an effect).

Good choice on the oil. Isn't that oil called Max-Life? I stay away from fram oil filters...havn't heard a good thing about them. Fram air filters are excellent.

Not sure if it was brought up before since I first read this thread awhile ago. Maybe an alignment may make a difference or at least have it checked.

Not a good choice on oil, it is the wrong oil type!
Our cars require 5W-20. Not 5W-30, nor 10W-30!!!
It should also say, "Fuel Conserving," I don't see that on the bottle.

Hold up, I know my oil cap says 5W30. The K24 in the 2003+ Accords takes 5W20.

Hold up, I know my oil cap says 5W30. The K24 in the 2003+ Accords takes 5W20.

My 02's cap and owner's manual specify 5W20.

Hold up, I know my oil cap says 5W30. The K24 in the 2003+ Accords takes 5W20.

+1...same thing for my 99. Not sure what year it was changed.

Per Honda Service Manual the recommended motor oil.
5W-30 up to 2000
5W-20 after 2000

My 02's cap and owner's manual specify 5W20.

Yeppers! Got Mobil One 5W-20 in my engine! :thmsup: :yes:

OK. I reread your post..

You stated your:
1) Using 5W-30, Your car needs 5W-20, "Fuel Conserving."
2) 45 PSI is likely too high. If the side of the tire said 45 PSI, that Maximum. I would not go over 40 PSI.

Your Fuel economy problem, may be an accumulation of problems:
Maintenance (update you cars service).
Use the proper oil (5w-20).
Wide or bigger tires can effect fuel economy.
Fuel used? I found that I repeatably got poorer fuel economy using CostCo Gas (temporarily change to Chevron gas for s
everal tank fulls, see it this has an effect).


1) manual states 5w-30 is fine, dealer said its fine especially in the summer of TX.
2) My tires are not for the stock rims, they are for my 18" they are low pro and require a higher psi. No 45 is not the max rating.

edit: car is not lowered, as far as mods under the hood, I do have a 200A Iraggi alternator, does 130A on idle, all wires have upgraded to 1/0awg(power, ground, ground to chasis; i.e. the "Big 3"). and the rest is all stereo mods for my SQ competitor system. Only thing dampened is my doors and trunk. I am not packing on that much weight unless I am carrying my all my camera equipment for work.

1) manual states 5w-30 is fine, dealer said its fine especially in the summer of TX.
2) My tires are not for the stock rims, they are for my 18" they are low pro and require a higher psi. No 45 is not the max rating.

edit: car is not lowered, as far as mods under the hood, I do have a 200A Iraggi alternator, does 130A on idle, all wires have upgraded to 1/0awg(power, ground, ground to chasis; i.e. the "Big 3"). and the rest is all stereo mods for my SQ competitor system. Only thing dampened is my doors and trunk. I am not packing on that much weight unless I am carrying my all my camera equipment for work.

5w-20 is what it said on the cap when I hauled off with it at the dealer and that is what goes in it.

Do you all think I might be in trouble for using a 75000 mile oil when my car was a few thousand short of 75000?? like 72 or 73xxx??

What is the size of the tires your using? Ex. 205-65-15.
When I had a 1984 Accord (4-cylinder), I changed out the 13-in (175-75-13?) tires and rims for 15-in (195-60-15, I think) tires and rims. About the same size around, just wider and less tire sidewall. I was getting high 20-ies (27-30MPG), after the rim/tire change, I was only getting LOW/Mid 20-ies (24-26MPG). The previous owner (a friend) said he was getting low 30-ies, but he drove no faster than 55 MPH, and I dont...

Did you also replace the cap, rotter, wires, PVC?

When I had a 1984 Accord (4-cylinder), I changed out the 13-in (175-75-13?) tires and rims for 15-in (195-60-15, I think) tires and rims. About the same size around, just wider and less tire sidewall. I was getting high 20-ies (27-30MPG), after the rim/tire change, I was only getting LOW/Mid 20-ies (24-26MPG). The previous owner (a friend) said he was getting low 30-ies, but he drove no faster than 55 MPH, and I dont...


Ahhh, good point. :thmsup: There is more rolling resistance with bigger wheels. It's easier to turn a 15" wheel than it is to turn an 18" wheel.

And A 200A alternator, is likely draws more parasitic load, from the engine. I suspect not that bad under low load...

Wider tires, -2 MPG
Thicker oil, -1 MPG
AC on all the time, -2 MPG (especially if recirculate (MAX AC) is on.
___________________________
FE losses....... -5 MPG

This is from the same 2002 EX 2.3 VTEC automatic in the last year.
California freeway commute (60-80 mph) of 24 miles (38 km) one way (5/95 - city/hwy): 28-29 mpg (12 km/L).
Alberta city commute (30-45 mph) of 7.5 miles (12 km) one way (95/5 - city/hwy): 25-26 mpg (10 km/L this includes wintertime idling at start-up to take the snow and ice off the windsheild).