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Discussion Starter · #1 ·
I guess that's an achievement of some kind, being in the top 5% of gas guzzlers among 7th-generation 4-cylinder Accords.

So, I'm seeking advice. Since I bought the Accord in July, I've done the following:

- Replaced spark plugs
- Replaced both O2 sensors.
- Re-oiled old, dirty K&N air filter.
- Cleaned throttle body.
- Seafoamed.
- Oil change with Mobil 1 5W-20.
- Drain and fill ATF (only 1x so far), plus Magnafine Transmission Filter.
- Dumped PEA fuel injector cleaner into gas tank.
- Verified tire inflation.
EDIT:
- Pinched off PCV valve with engine running to verify correct operation.
- Performed idle learn/reset as per factory instructions.


And after all that, how am I doing, 9 fill-ups and 3,000 km later?

20.6 MPG (11.4 L/100km)

Nothing I've done seems to have made a noticeable dent in the mileage.

The car's mostly driven in town, but it's a small city with no traffic snarls to speak of. My wife's not the most efficient driver, but neither is she a leadfoot.

I guess someone has to be out near the ends of the bell curve, but still. Any advice?
 

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Small point, but you are converting Imperial gallons to US gallons, right? Because 11.4 liters equals 3.01 US gallons.

Are you using E0 gasoline (no ethanol), E10 (10% ethanol), or some non-verifiable brand that can have as much as 12% ethanol?

And your spark plugs and O2 sensors are which brand?
 

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Discussion Starter · #3 ·
Small point, but you are converting Imperial gallons to US gallons, right? Because 11.4 liters equals 3.01 US gallons.

Are you using E0 gasoline (no ethanol), E10 (10% ethanol), or some non-verifiable brand that can have as much as 12% ethanol?

And your spark plugs and O2 sensors are which brand?
Spark plugs are the NGK OEM replacements, and O2 sensors are Denso OEM. The car was throwing codes for both sensors when I got it, and running in open-loop mode due to the A/F Ratio Sensor being bad. I drove it for several weeks before replacing the A/F Ratio Sensor, so I had hoped that replacing it would improve gas mileage, but no such luck.

My main gas station (a local co-op) uses regular Shell gas, but I've also used Petro-Canada and Esso gas without noticing any differences. I believe it's all E0 gas.

Finally, the units conversion comes straight from the Fuelly site. But you're correct, the MPG figure is using US gallons.
 

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wow that sux! im waiting to fill my 05 up for the second time as of yet. going by the gas gauge witch really doesn't mean accuracy, but at half tank i got 34.3 mpg. will see if that holds at the next fill up. hope it does. do you do jack rabbit starts? meaning get up to speed quick? if so that's going to hurt your over all mpg drastically. maybe your wife is driving harder when your not with her. got any kids at driving age?
 

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Discussion Starter · #5 ·
wow that sux! im waiting to fill my 05 up for the second time as of yet. going by the gas gauge witch really doesn't mean accuracy, but at half tank i got 34.3 mpg. will see if that holds at the next fill up. hope it does. do you do jack rabbit starts? meaning get up to speed quick? if so that's going to hurt your over all mpg drastically. maybe your wife is driving harder when your not with her. got any kids at driving age?
No kids at driving age until next year. But I used the Torque OBD App for Android to measure the instantaneous fuel economy on a couple of drives I did, and 21 MPG is about where it ends up, even with gentle starts.

The car has about 112,000 miles, runs and shifts smoothly and is in pretty good shape overall. It replaced a Nissan Quest which only got about 16-17 MPG, but based on the Fuelly averages, I was expecting the Accord to hit the mid to high 20s, so it's a bit disappointing.
 

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Bob's your UNCLE ...
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.... 7th-generation 4-cylinder Accords.

I've done the following:

- Replaced spark plugs
- Replaced both O2 sensors.
- Re-oiled old, dirty K&N air filter.
- Cleaned throttle body.
- Seafoamed.
- Oil change with Mobil 1 5W-20.
- Drain and fill ATF (only 1x so far), plus Magnafine Transmission Filter.
- Dumped PEA fuel injector cleaner into gas tank.
- Verified tire inflation.

And after all that, how am I doing, 9 fill-ups and 3,000 km later?

20.6 MPG (11.4 L/100km)

The car's mostly driven in town, but it's a small city with no traffic snarls to speak of?
So, you're experience and your daily use seems VERY similar to my use on my '07 (also an i4 with the 5AT) ... I too was getting crap gas milage when I first got the car this past July, compared with some of the posts I'd read on this site, a bit lower than what you've posted actually - @ 19mpg ...

Going from your above list of maintenance, the only difference I can see, is that I also cleaned my MAF sensor, and performed an ECU reset / idle relearn ... and now I'm seeing 500km per tank or better on a very consistant basis.

Off a tank of 87 octane from Shell (E10 for Rick :wave:) i'll usually get just over 500km off ~50 litres ... the last tank of 89 (also E10) netted me 550km, and I'm currently halfway through a tank of 91 (E0) at just over 300km ... I maintain 36lbs in my tires if that's any help.

9 fill ups over 3000kms is not good ... I'd have done 6, or $180 less for the same distance. IIRC, 20mpg city is what these cars are listed at for fuel milage, so I'm very happy sitting at 25. I did manage to net 32mpg doing a full highway run down to Portland back in August, so do an idle relearn PRONTO !!
 

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a girl at work has a 03 and clames she gets 34 regularly. my 05 got 34 at half a tank. cant quantify that till i fill up though. maybe time for a complete tune up including air filter. set your tires as per the sticker in the drivers door jam.
 

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Bob's your UNCLE ...
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a girl at work has a 03 and clames she gets 34 regularly. my 05 got 34 at half a tank. cant quantify that till i fill up though. maybe time for a complete tune up including air filter. set your tires as per the sticker in the drivers door jam.
Shaggy - your 34 is city or highway ?

I'm not certain, because I was pretty hammered last time I was on Vancouver Island, but I think there's quite a bit of "up and down" elevation changes on those roads just like here on the mainland.
 

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Discussion Starter · #9 ·
@bobbo

I forgot to mention that I also did an idle learn/reset cycle. The one where you jumper the battery leads for several minutes with the ignition turned to On, then run the engine at 3,000 rpm until the fan turns on twice or the coolant hits ~92 °C? Yeah, did that a while back.

But I wonder if it's possible that the ECM is bad. It was throwing a P0685 code when I got it, which cleared after I cleaned the (green and fuzzy) battery terminals, but maybe there's something else going on there.

Otherwise, the terrain around Victoria is hilly, but our most common driving routes into and out of town are pretty flat.

@shaggy

I did the air filter and the tires, and a bunch of other low-hanging fruit. Even some not so low-hanging fruit, like O2 sensors, plugs, and throttle body. Oh, also verified correct operation of PCV valve. Not sure what else would be included in a tune-up: a valve job? Anything else?
 

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Shaggy - your 34 is city or highway ?

I'm not certain, because I was pretty hammered last time I was on Vancouver Island, but I think there's quite a bit of "up and down" elevation changes on those roads just like here on the mainland.
combined. ive never had a complete tank either direction. unless your on vacation i highly doubt anyone ever does a full tank either way. id say 70% city 30% highway as the norm for me, BUT remember that's from the gas gauge. not after fill up.
 

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616Nickel

a valve job no. if you were low on power id then do a compression check first. if a low cylinder then add a table spoon of oil then recheck. pressure comes up it would be rings. if not a valve issue, but you didn't say if it was low on power.

ill be honest i sux at diagnosing problems, but can usually fix it when i ow what the problem is. basically im a great r+r guy.
 

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shaggy: Good point. A "poor man's" method is to send an oil sample out to a place like Blackstone Labs in Indiana for an oil analysis. If there are unacceptable amounts of gasoline in the oil, they will tell you and tell you why.
 

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Discussion Starter · #13 ·
616Nickel

a valve job no. if you were low on power id then do a compression check first. if a low cylinder then add a table spoon of oil then recheck. pressure comes up it would be rings. if not a valve issue, but you didn't say if it was low on power.

ill be honest i sux at diagnosing problems, but can usually fix it when i ow what the problem is. basically im a great r+r guy.
Thanks for the advice, shaggy.

I don't know if it's low on power, since I've never owned an Accord before. It doesn't feel unreasonably low for the car's size and weight, and on-ramp acceleration is never a problem. The car does seem to upshift early, so that it lugs at a little under 2,000 rpm at (say) 40 mph, but I assumed that's intentionally designed in to keep revs low.

Compression: The Boost (intake manifold) pressure reads in the normal range while driving, according to the Torque OBD app. Or should I get a proper compression test done?

All in all, though, I seem to have taken all the routine steps to improve fuel economy. At this point, I can't imagine finding a silver bullet that would take my car even into the mid-20s, let alone higher.
 

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khol
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Make sure you do not continually run the front windshield vent as it turns on the AC and doesn't let you turn it off. There is a thread on how to override this so that you can turn on and off the AC so that you do not have to continually have to the AC running. In my experience the AC drops my mpg by about 2 in mixed driving.
 

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ya the hack is very simple, and quick. forgot bout that. thanks for reminding me khol. LOL did it last night too.

other thought you got a heavy foot? that app you got is there a droid version? whats it called? lazy me.
 

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Discussion Starter · #16 ·
ya the hack is very simple, and quick. forgot bout that. thanks for reminding me khol. LOL did it last night too.

other thought you got a heavy foot? that app you got is there a droid version? whats it called? lazy me.
No heavy foot, no. And I'd really have to be mashing the pedal to kill the mileage that badly!

The app is called Torque, and it's Android. There's a wiki for it here. You'll also need a Bluetooth OBD adapter, but it gives you access to a ton of real-time data from your car.

Can someone provide a link to the thread on hacking the windshield vent?
 

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a girl at work has a 03 and clames she gets 34 regularly. my 05 got 34 at half a tank. cant quantify that till i fill up though. maybe time for a complete tune up including air filter. set your tires as per the sticker in the drivers door jam.
34 mpg with 70% city driving? That seems a little too good to be true (or you must be great at hypermiling ;))...I wonder if you would get the same #s if you calculated it after a full fill-up. The 4-cyl accords are rated for 21/31 and I think the best I've ever done on the highway is about 35-36 mpg. In normal city driving I'm usually around 23-25 mpg.
 

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I average 16.86 mpg in my 4 cyl over 5 fillups. i think the location of where you drive plays a big factor too. NYC, lots of stop and go, kills my mpg.

07 i4 5AT ~45k miles btw.
 
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