Okay i had thought it was normal untill i mentioned it to another SVT owner. Everytime i fill i alwayus check the gas mileage and i always get 19. granted, most of the time it is all suburban driving but this last tank was some highway too and still 19.

Also, this last tank i had made it a point to drive very conservatively: trying to shift below 3000 when possible.

What could be wrong that is causing this? Could some things need cleaned?



Thanks,
Ryan

Perhaps your math is off.


Outline your routine for determining milage, and we'll go from there (using actual numbers where available)


Ray

Also check tire pressure.

okay. i always fill up the tank and top it off twice (two more times that the pump auto shuts off) every time i write down the mileage and the recipt tells me how many gallons. so then the MPG should be the number of miles i went on the tank devided by the number of gallons it took to fill it back up. my recipt today:

224.2 Miles (down to about 1/8 a tank but fuel light not on)
11.265 Gallons of Sunoco 93 Octane.

224.2 Miles / 11.265 Gallons = 19.902 Mpg

and its always like that. always in the 19s i have to go home this weekend to get some stuff and i'll dig up some of my other recipts (theyre laying around somewhere) and show some other numbers if needed.

edit: tire pressure is kept at 32 all around, as the door sticker states.

Any CELs? Engine running smooth?

for one, You are creating a slightly false low by topping off twice.

In actuallity, you should:

Use the exact same pump every time (not always a viable option)


Basically, by topping off at all, and being at different pumps, that changes things. Each station, and each pump (for that matter) is triggered at different rates, so topping off at ONE pump twice may allow a quarter gallon in. Others, an 1/8th, or more than a 1/4.

Always fill the exact way (until it shuts off the first time, etc) By topping off the the "nearest dollar" or "twice" (as you do) you are adding more fuel than you ACTUALLY consumed. You then do the math and are dividing those miles by MORE fuel than you originally clicked off at.

Other than math, or topping off:

check your fuel filter... air filter (clean if open air, or replace if stock), plugs/wires, and MAF cleanliness.


Ray

One other thing. Calculate mileage based on this amount of gas from this fill to next fill. (not fill this time and calculate mileage from previous fill).

I think Tony is saying:

Empty your tank.. pump gas, and see that you got... 11.29 (example) gallons.

THEN drive until you decide to refill and look at mileage. Calculate using those figures.

Ray

but its not more fuel than i actually consumed if i do that every time. that way it always starts from the same point and when i was home, i did go to the same pump at the same station.

edit: how do you all calculate your MPG's?

Then maybe you need to,

"check your fuel filter... air filter (clean if open air, or replace if stock), plugs/wires, and MAF cleanliness."

Ray

But it isn't "always" starting from the same point. Different pumps, different stations, even different temperatures and humidity can cause the actual amount fueled when "topping off" to be more, or less than the time before it. not a drastic amount, but still there.

If the previous suggestions for maintenance don't help. I SERIOUSLY suggest a UIM/LIM teardown and cleaning. you can't mess it up with the HOW-To posted in the Duratec Maintenance FAQ. With more than 33K miles on your engine, you're likely getting pretty dirty. Restore stock horses, and increase your current mileage with this procedure.




Ray

Okay, folks, my '95 Mystique with the 2.5, CD4E gets 25 MPG give or take 1/4 gallon. I almost always fill up at the same station. I fill it the same way every time. My driving from Mon. to Fri. is the same "to work and back", 30 miles round trip per day. Weekends I put on any where from 75 to 275 miles (I fill up on Fridays before work, mostly). Most of my driving is on a freeway @ 68 MPH. On 2 occasions I got 27 MPG. I usually fill up at around 1/4 tank. Tyre pressure is 44PSI per tyre manufaturer (Kelly Charger 205-50-15). I replaced the air filter shortly after I got this car in July. Actually runs crappier since then; Fram filter. The one I replaced was whatever CARX uses. Another bad thing I did after I replaced the filter was to put in a bottle of Gumout fuel injector cleaner. Since then I let the car idle for about 2 to 5 minutes in the morning, otherwise it acts like it is starving for fuel. Is 25 MPG normal for this type car, engine, trans?? And to say also, I got this type of mileage before the filter and Gumout situation. Car has 94700 miles.

Later. Pepse.

Originally posted by Pepse:

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I replaced the air filter shortly after I got this car in July. Actually runs crappier since then; Fram filter.

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Maybe the air filter or housing is not seated properly.
Also clean the MAF and IAC valve, and replace the fuel filter if it has not been replaced in the 12 months.

Edit. This thread might help.
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=1037329&page=3&view=collapsed&sb=5&o=7&fpart=1