14MPG WTF?
10-04-2007, 08:23 AM
#1
14MPG WTF?
Hello. I just went 64 miles on almost a quarter of a tank. I thought that was real odd so I filled it up, and calculated 14MPG. It is ridiculous; I usually get 20-22MPG. I do not know what is wrong. I used the same gas I always use. I put fuel injector cleaner in 3 weeks ago. No CEL. What could be the problem? I changed the fuel filter a year ago, 10,000 miles. Oil change not even 1,000 miles ago. Does anyone have a clue. I am thinking it may be the knock sensor, maybe? I need some help.
10-04-2007, 08:29 AM
#3
Yes. Mine fluctuates a lot. The thing is I bought 4.5 gals of gas after traveling 64 miles. That turns out to be: 14.2 MPG which is no where near it needs to be. Meaning something is wrong with my car.
10-04-2007, 08:44 AM
#6
I’m confused. 
You had a ¼ tank, used it in 64 mi, filled it to what you thought was another ¼ tank, and calculated from there?
If that is indeed the case, everyone is correct, the gauge is merely an indicator/reminder. (Qualitative vs Quantitative)
You had a ¼ tank, used it in 64 mi, filled it to what you thought was another ¼ tank, and calculated from there?If that is indeed the case, everyone is correct, the gauge is merely an indicator/reminder. (Qualitative vs Quantitative)
10-04-2007, 08:47 AM
#7
I didn't know I was confusing people. Here is what happened. I filled up a full tank of gas Monday. Went 64 miles in 3 days. The tank was down 1/4; 3/4 full. I filled up with 4.5 gallons of gas, topping off the tank. And got 14 MPG. Hope this clears it up. Now I need to know what is wrong, if anything. I'll check what cleaner I got.
10-04-2007, 09:01 AM
#8
maybe you were real heavy on the foot for a few days. i wouldnt worry about it until you notice this happening for awhile. probly just some random thing and itll be back to normal. (assuming your car is fine and didnt throw any codes)
10-04-2007, 09:04 AM
#9
I didn't know I was confusing people. Here is what happened. I filled up a full tank of gas Monday. Went 64 miles in 3 days. The tank was down 1/4; 3/4 full. I filled up with 4.5 gallons of gas, topping off the tank. And got 14 MPG. Hope this clears it up. Now I need to know what is wrong, if anything. I'll check what cleaner I got.
10-04-2007, 09:12 AM
#10
Maybe this will help? http://forums.maxima.org/showthread.php?t=539969
10-04-2007, 09:32 AM
#11
I didn't know I was confusing people. Here is what happened. I filled up a full tank of gas Monday. Went 64 miles in 3 days. The tank was down 1/4; 3/4 full. I filled up with 4.5 gallons of gas, topping off the tank. And got 14 MPG. Hope this clears it up. Now I need to know what is wrong, if anything. I'll check what cleaner I got.
By 'topping off the tank' do you mean continuing to fill it after the pump clicks off? That will skew your results.
...please god, not another mileage thread...
10-04-2007, 09:47 AM
#12
Each pump will top off at a different level. IME this can be as much as a gallon difference.
But a couple months ago I managed to get 15mpg for most of tank which seemed really bizarre. But then it was normal (25mpg) on the next tank. Perhaps the gas was bad and tripping the knock sensor, I dunno but if mileage is the same for a few tanks in a row you know you have a problem.
Dave
But a couple months ago I managed to get 15mpg for most of tank which seemed really bizarre. But then it was normal (25mpg) on the next tank. Perhaps the gas was bad and tripping the knock sensor, I dunno but if mileage is the same for a few tanks in a row you know you have a problem.
Dave
10-04-2007, 09:59 AM
#13
my gas gauge won't move below the fill line until after 100 miles. The top quarter of the tank gives be about another 100 miles with each successive quarter giving me different mile-age. The only real way to tell is drive your tank till empty, fill it up completely and then drive it to empty again and recalculate.
Check your tire pressure as well.
Check your tire pressure as well.
10-04-2007, 12:39 PM
#16
10-04-2007, 03:28 PM
#17
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my gas gauge won't move below the fill line until after 100 miles. The top quarter of the tank gives be about another 100 miles with each successive quarter giving me different mile-age. The only real way to tell is drive your tank till empty, fill it up completely and then drive it to empty again and recalculate.
Check your tire pressure as well.
Check your tire pressure as well.
There is a more accurate way!!
Wait till the gas light comes on steady on a flat surface, immediatly hit the trip button, when you fill up add exactly 10 gallons (makes the math easier) than, next time the light comes on steady again, look at the trip. 243 miles= 24.3 mpg. It's not only easier, but it's more accurate for several reasons..........
10-04-2007, 03:31 PM
#19
There is a more accurate way, Wait till the gas light comes on steady on a flat surface, immediatly hit the trip button, when you fill up add exactly 10 gallons (makes the math easier) than, next time the light comes on steady again, look at the trip. 240 miles= 24.0 mpg. It's easier, and more accurate for a couple of reasons..........
10-04-2007, 03:36 PM
#20
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Fill up, hit the trip botton to zero...drive till 1/4 tank is left, fill up again and devide how many miles you paid for, into the gross mileage you drove on the trip clock (13.4/340)
Thats the right way to do it !! Discussion Over.
-matt
Thats the right way to do it !! Discussion Over.
-matt
10-04-2007, 03:37 PM
#21
you need a more accurate system my friend. this is what i do:
start with a full tank. then set odometer to 0
next trip to gas station fill it up (pay with a card).
write down miles traveled on receipt and reset odometer
when you get home you know how many miles you went for whatever GAL on the receipt
start with a full tank. then set odometer to 0
next trip to gas station fill it up (pay with a card).
write down miles traveled on receipt and reset odometer
when you get home you know how many miles you went for whatever GAL on the receipt
10-04-2007, 08:38 PM
#22
my gas gauge won't move below the fill line until after 100 miles. The top quarter of the tank gives be about another 100 miles with each successive quarter giving me different mile-age. The only real way to tell is drive your tank till empty, fill it up completely and then drive it to empty again and recalculate.
Check your tire pressure as well.
Check your tire pressure as well.
lol you sound like Mario Andretti on that Firestone commercial
10-04-2007, 08:53 PM
#24
There is a more accurate way!!
Wait till the gas light comes on steady on a flat surface, immediatly hit the trip button, when you fill up add exactly 10 gallons (makes the math easier) than, next time the light comes on steady again, look at the trip. 243 miles= 24.3 mpg. It's not only easier, but it's more accurate for several reasons..........
Wait till the gas light comes on steady on a flat surface, immediatly hit the trip button, when you fill up add exactly 10 gallons (makes the math easier) than, next time the light comes on steady again, look at the trip. 243 miles= 24.3 mpg. It's not only easier, but it's more accurate for several reasons..........
10-04-2007, 09:02 PM
#26
The short answer: A 1/4 tank of gas and 64 miles is not enough to conclude anything. Run a few tanks of gas through and then see.
P.S. Don't run your car till the light comes on, that's not good for an older car.
P.S. Don't run your car till the light comes on, that's not good for an older car.
10-05-2007, 08:09 PM
#27
stop driving with your foot on the floor! or ... stop shifting at 7 grand every time! lol sounds like you could possibly have a bad FPR ... or really really dirty injectors. You can pull the injectors to really clean them if you get ****, but typically a take of high octane and some cleaner makes it good to go.
10-05-2007, 09:47 PM
#30
are you pulling any codes at all ???? Good call Matt on the o2 sensor. I wouldn't do the injectors unless you really needed to. Like Matt said, till be a beotch of a job to do the rear bank. But .. while ya got that intake off, get a MEVI or 00vi FTW!!!!!
10-06-2007, 05:29 AM
#31
10-06-2007, 08:41 PM
#32
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Join Date: Aug 2006
Location: somewhere in Maryland
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64 miles in three days... Lets see how many short trips you made during those days? How many times you left the car running for whatever reason? Did you warm up the car before driving it? How's your driving style? Like others said, 1/4 tank of gas doesn't provide enough data
10-06-2007, 08:45 PM
#33
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64 miles in three days... Lets see how many short trips you made during those days? How many times you left the car running for whatever reason? Did you warm up the car before driving it? How's your driving style? Like others said, 1/4 tank of gas doesn't provide enough data
In the summer 30 seconds is MAX thats needed on a cold start, in the winter 60 to 90 seconds is all that is needed
All you have to do is drive slowly until the car BEGINS to heat up, meaning not let the rev gauge past the 3000 rpm mark
10-06-2007, 08:53 PM
#34
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Join Date: Aug 2006
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Posts: 241
Actually for your knowledge, warming up the car wastes gasoline
In the summer 30 seconds is MAX thats needed on a cold start, in the winter 60 to 90 seconds is all that is needed
All you have to do is drive slowly until the car BEGINS to heat up, meaning not let the rev gauge past the 3000 rpm mark
In the summer 30 seconds is MAX thats needed on a cold start, in the winter 60 to 90 seconds is all that is needed
All you have to do is drive slowly until the car BEGINS to heat up, meaning not let the rev gauge past the 3000 rpm mark
10-06-2007, 10:27 PM
#36
I not sure what " 1/4 tank crap " your referring to.
He obviously knows how to calculate his mileage based on his statement.
All I am saying is not to panic and start throwing parts at a problem that might not exist. keep a tab on your mileage and if it continues to be low, than yes there is a problem.
Last edited by 67whitegoat; 10-06-2007 at 10:48 PM.
10-06-2007, 11:17 PM
#38
Acually, it is. Have you ever had the tank off of a 10 year old car to see the crap that's in the bottom of it? Be nice to you fuel system and don't run it below a 1/4 tank.
I not sure what " 1/4 tank crap " your referring to.
He obviously knows how to calculate his mileage based on his statement.
All I am saying is not to panic and start throwing parts at a problem that might not exist. keep a tab on your mileage and if it continues to be low, than yes there is a problem.
I not sure what " 1/4 tank crap " your referring to.
He obviously knows how to calculate his mileage based on his statement.
All I am saying is not to panic and start throwing parts at a problem that might not exist. keep a tab on your mileage and if it continues to be low, than yes there is a problem.
10-07-2007, 09:21 AM
#40
Dave