Gas mileage has gone to shit. Why?

[ls2poweredgoat 5,000+ posts]

2001 Honda Accord, 4-banger 5-speed, car only weighs 3,000 lbs. I'm only getting 350 miles to a tank, with a 16 gallon tank, which averages out to approx. 22 mpg.

For example, my dad drives a 2006 CTS sport w/6-speed and in stop and go driving, he's averaging 22 mpg, and he doesn't drive like a 95 year old man either...BUT...he doesn't drive as hard as I do..

I changed the spark plugs when I bought the car, but I didn't change any thing else. Original o2 sensors (two of them).

I have a Megan Racing header/test pipe on there...which actually...when I put them on, gave me quite a boost in gas mileage. I also added an Ebay short ram air intake, that helped too. The 2nd o2 sensor rests in the test pipe, and seeing that my car originally is ULEV (Ultra Low Emissions Vehicle), my check engine light is always on, because it "isn't meeting emissions", with the test pipe.

I drive the car somewhat aggressively, but not nearly as much as my friends do. I've been doing a lot of highway driving, especially on the last 2 tanks, and my gas mileage doesn't show it.

Granted, I do 95 mph on the highway, but still.

Last summer I was getting 400-460 miles to a tank, most of it being stop and go traffic...which averages 25 - 29 mpg.

I'm thinking of replacing the o2 sensors and spark plug wires, both of which are original. Car has about 110,000 miles on it...

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[dman4486 5,000+ posts]

95mph

/thread

 

[jco1385 5,000+ posts]

how long since you did plugs, oil change, and cleaned the air filter/MAF??

 

[TurdFergueson2 5,000+ posts]

Have you tuned it up?

 

[THUMPPER 10+ year member]

your catylatic converter on the exhaust is probably plugging up....

 

[shaneb 10+ year member]

Replace spark plugs, wires, distro cap, air filter, get a compression test an stop driving 95

 

[ls2poweredgoat 5,000+ posts]

95mph

/thread

But that burns less gas then stop and go city driving, with a light every half mile, going through 1st and 2nd gear...

At 85-95 mph my car runs 3,000 rpm...

I replaced the spark plugs 50,000 miles ago, I put in nice ones too.

 

[ls2poweredgoat 5,000+ posts]

Replace spark plugs, wires, distro cap, air filter, get a compression test an stop driving 95

Yeah, I'll do all of the above.

It just pisses me off because last summer, in PURE stop and go traffic, driving the car like I always do, my record was 468 miles to ONE tank.

 

[dman4486 5,000+ posts]

But that burns less gas then stop and go city driving, with a light every half mile, going through 1st and 2nd gear...
At 85-95 mph my car runs 3,000 rpm...

I replaced the spark plugs 50,000 miles ago, I put in nice ones too.

oil makes a huge difference on small engines

as does the air filter.

also because the weather is colder, the engine will compensate for the more dense air and use more gas

 

[grassroots 10+ year member]

95mph

/thread

yah... really...

you know how hard your little 4 cylinder economy car has to work to keep it at 95?

 

[Louisiana_CRX 5,000+ posts]

winter gas is not as strong as summer gas almost everyone gets less mpg in the winter

 

[dman4486 5,000+ posts]

yah... really...
you know how hard your little 4 cylinder economy car has to work to keep it at 95?

that was my point, but I am not in an arguing mood today

 

[HypnoticCure 10+ year member]

3000 rpms will burn quite a bit of gas... drive slower and do the regular maint on your car. Also it may be time to go back to something lsx based... think about it... most of them get better mpg then that 4 banger honda...

 

[ls2poweredgoat 5,000+ posts]

oil makes a huge difference on small engines
as does the air filter.

also because the weather is colder, the engine will compensate for the more dense air and use more gas

I live in Florida...

I run Mobile-1 Full Synthetic, and change the oil every 5,000 miles or so.

you know how hard your little 4 cylinder economy car has to work to keep it at 95?

True, but I was doing the same last summer, and my gas mileage wasn't so shitty. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[lincolntc690 10+ year member]

its the high velocity grease in your muffler bearings or the canooter valve

jk