I have a '91 Accord with about 187,000 km (about 116,000 miles).

When I filled up the gas tank last, I pushed the tripmeter button to reset it to 0.
I drove 425 km (about 264 miles) on one tank. I usually don't let the tank go so low, but I waited until the gas tank light came on to fill it; so it was about 17 gallons.

I'm not the best at math, but to me that means 264 miles divided by 17 gallons; equals about 15.5 miles per gallon, which is obviously very low.

At first I thought I made a mistake, but I double-checked everything, and it's right.

Then I thought there must be something wrong with the car; although I just bought it, had it checked by a mechanic first and after; had an oil change, transmission fluid change, etc.

THEN I thought maybe it's because the tires on the car are slightly bigger than the recommended size. A friend who works with tires said that the difference in tire size would throw the speedometer off by something like 2 km/hour (only about 1 mile/hour). So obviously the odometer and tripmeter would be off too.

I saw a thread in here somewhere about how many mpg everyone got. I know the '91 accord was supposed to get about 22-24 mpg; but I'm guessing that's when it's brand new, and it probably gets less after 13 + years?

Does anyone have any ideas about why I got such a low mpg?

 

It is a combination of things...

I would check/replace as needed the following:

Spark plugs/wires
o2 sensor
Catalytic converter
Run some fuel systems cleaner (bg44k or seafoam )
Fuel filter
Air filter
Tire pressure
Tire wear (rotated and balanced?)
Driving habits

 

min is a 90 and i get 25 MPG city consistently... when ur driving the light actually comes on more around 14-15... theres about 2 gallons of reserve gas in there for emergencies. so its more like you got around 17.5-18 or so. which is still horrible. are you a leadfoot driver? you said you had bigger wheels on there...are they aftermarket? what size? some aftermarket wheels weight a whole hell of a lot more than OEM wheels so they make the engine work harder to push the car because of the added rotational mass. so this will make you consume more gas. ur not throwin any codes or anything are you? maybe your tires are underinflated, that can also cause worse gas mileage... maybe your spark plugs are goin out, plug wires even... you might need a tune up. there are lots of factors involved really.

 

Thanks for the replies!

I searched the internet for the tire/odometer thing; and one place said that a slightly bigger tire would have the odometer read low by about 4%. So taking that into consideration, it would come to just 16 mpg.

The original tires were: 195/60R15
The tires it has now are: 195/65R15.

If there's about 2 gallons left after the light comes on, that would make it up to about 18mpg, as you said - still horrible! (That tank was all city driving).

One day a few weeks after I bought it, I started having trouble starting it. It would start okay, but it took about 2-4 seconds to start. I bought new (platinum) spark plugs, because I saw that the old ones were terrible. That seemed to solve the problem.

Now, I only seem to have trouble starting (it takes just a bit longer) on wet days. A few people have suggested changing the distributor cap.

I'm not a leadfoot or crazy driver at all.

I just replaced the air filter also.

Tire pressure is good, I've checked it a few times.

Had the tires rotated when I had the oil changed.

I used a high mileage fuel injector cleaner once, about 3 gas tanks ago.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VRDrvr &raquo;</TD></TR><TR><TD CLASS="quote">It is a combination of things...

I would check/replace as needed the following:

Spark plugs/wires
o2 sensor
Catalytic converter
Run some fuel systems cleaner (bg44k or seafoam )
Fuel filter
Air filter
Tire pressure
Tire wear (rotated and balanced?)
Driving habits

</TD></TR></TABLE>

i got a valve adj, and ran 2 bottles of concentrated Chevron Techron though my tanks, and it added about 5mpg.....im not getting nearly 30/25 (94 EX)

 

P.S. it's an automatic; I've been using 91 octane fuel like the manual says.

 

i use cheap gas and i get 290 to 330 miles to a tank depends on drivn habit that week 91 accord lx 130,000

 

it actually says 91 in the manual? with a low compression engine like the f22a1, you really should be saving ur money and just run 89. its what ive been runnin and its perfectly fine. 91 isnt really needed. but if you wish to stay that way because the manual says, then hey, i guess it couldnt cause too much harm considering honda says so...

 

i use 87 on my f22b.....NO need for anything higher on 8:1 comp engines

manual says to use 91 octane?!?!?!?!?!?!....is this an H22 4th gen or somethuing???

 

whoops, ha i meant 87....ive got my octanes mixed up

 

Is it more slugish than it used to be? Either way I'd deffinitely check the O2 sensor. It's about that time. Mine went out in a 90 Eclipse I had with about the same miles.

Run Sea Foam and 44k on it. Check out https://honda-tech.com/zerothread?id=902955 for more into on those cleansors.

 

I might be wrong here, but don't 91 Accord's only have 15 gallon tanks?

I am 99% sure that mine has a 15 gallon tank. Maybe since yours is not an American car, it has a different size tank, but I can't be sure about that!

The best way to do the mpg test, is to fill it all the way up, hit the trip, drive her till she is about empty, then fill it back up, and compare the mileage to what the gas pump says you put back into it. You actually don't even have to run her empty, just go about 200 miles, and fill it back up.
You should be getting over 20 mpg.

My 91 with 282,000 was getting 22-23 before I pulled the motor out. And for the critics, that was with 87 octane.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91AccordSE &raquo;</TD></TR><TR><TD CLASS="quote">I might be wrong here, but don't 91 Accord's only have 15 gallon tanks?

I am 99% sure that mine has a 15 gallon tank. Maybe since yours is not an American car, it has a different size tank, but I can't be sure about that!

The best way to do the mpg test, is to fill it all the way up, hit the trip, drive her till she is about empty, then fill it back up, and compare the mileage to what the gas pump says you put back into it. You actually don't even have to run her empty, just go about 200 miles, and fill it back up.
You should be getting over 20 mpg.

we basically have a 15 gallon tank with a 2 gallon reserve which makes it a 17 gallon tank. but ive got somethin like 243000 on mine and im still gettin 25 and im pretty sure i really need to change my air filter, so it could prolly be a lil better. but def always use 87 octane cuz thats all our low compression engines really need.

My 91 with 282,000 was getting 22-23 before I pulled the motor out. And for the critics, that was with 87 octane.</TD></TR></TABLE>

 

Alright, I stand corrected. That 1 % snuck up and bit me in the ***.

I have my owner's manual right here. Here is what it says:

GASOLINE : Unleaded Only Pump octane of 86 or higher.

Gas-Tank Capacity: 64.5 l (17.04 US Gal, 14.19 lmp gal)

I usually just head to the pump when it is convenient after my fuel light illuminates. I bet I have only put in over 14 gallons once or twice. I have never got more than 15 in it. That is why I thought it was a 15 gallon tank.

Ya learn something new everyday.