weird MPG

[evil-98]

this is my first week driving my 09 S Touring 5 door and i got about 230 out of my full tank. most all of those miles were highway. i drive about 60 miles a day going to work and back in high way and i barely got my car last Saturday.

so that would be 60 x 3(mon-wed) = 180 (highway) - 230 = 50 (city)

thats kind of crappy? 14.5 gal @ 30 mpg would = 435

im getting less then 20 mpg..?

maybe its a break in period?

edit:

its automatic

 

[my3needsaname]

The automatic is hell with gears but you should get about 24 highway average. At least, that's what I got when my hatch was brand shpankin' new. Now it does 19 highway and 17.5 city (city down from 21), dunno why but you also have to include how much you feather the throttle, speed, acceleration intensity...stuff like that.

I would give it a few hundred miles to get situated first then check it and see what you get.

 

[GoFast]

break in could be playing a small part in it. I think a lot of it could be you getting to know a new car and playing around with it so that could deplete some mileage. I was looking at your calculations and there are somethings to note. just because the tank is 14.5 gallons doesnt mean that should be your number for calculations. typically when my light kicks on i pump about 12.5-13 actual gallons so that should really be your number used to mpg calculations. With that being said, you probably actually go about 18mpgs. not great but like i said before i think driving habits could play a pretty big roll. Give it a few tanks and see if it gets better.

miles driven/gallons pumped

 

[evil-98]

well i drove like how i normally drive and i use to drive a V6 which got the same or better millage with a similar size tank. ive been cautious about driving and easing into my first couple thousands but i mean im driving alot easier then i use to and im getting similar mileage to when i use to drive hard.

 

[sanblaster]

22-29 is what is listed for the 09 automatic. bad in my eyes but I love the car so much.

 

[evil-98]

so just filled up an ran 53 miles on the first quarter tank.. WHATS GOING ON!!!

 

[flash75]

You cannot go by the gauge to determine fuel mileage. You haven't mentioned how many gallons it takes to fill your car. Computation of fuel mpg should be based on how much gas it takes to fill the tank, not what the guage reads. Gauges generally are not very accurate. For example.

My Protege 5 with automatic the fuel gauge will remain at the full mark for around 50 miles, reaches the 3/4 mark at around 125 miles driving at highway speeds. After that it falls quickly. Highway mpg is is usually around 29-30.

The gauge on my Mazda 3i 4door with 2 liter engine and automatic will drop to the 3/4 mark in around 75 miles, it then moves rather slowly until the 1/4 mark. Most all of my driving is highway miles. The car usually gets 32-34 MPG and has never been under 30 mpg in 10k miles since new. I usually drive close to the posted speed limits

Clifton

 

[my3needsaname]

so just filled up an ran 53 miles on the first quarter tank.. WHATS GOING ON!!!

I rolled 60 city when the car got good mileage. Now the gauge is still at 3/4 full with 60 on the trip...the gauge is INCREDIBLY inaccurate in my car. For example it runs about .5 gallons above what is actually in the tank...so I get .5 gallons of air-gas. Gas that isn't there but the car reads the air!

So yea, idk what to tell you. It seems every Mazda3 has some sort of problems...I guess one of yours is gas mileage? (dunno)

 

[tsunami]

dear lord seriously people... you are trying to tell milleage by how much is missing from your guage... thats just idiotic. do what the others have stated and divide miles driven by gallons you pumped into the tank that fill up and thats your mpg, then reset your trip and repeat. i would give it some time i know i lot of people had terrible gas milleage in the begining. if it doesn't improve just bring it to the dealer. also i would try using your cruise control it will do wonders for gas milleage... also when you say highway what speed are we talking exactly...???

just cause i can... last 3 tanks on my modified 04 5sp 32,34,32 and i am at 67k and deffinatly don't baby it.

 

[my3needsaname]

just cause i can... last 3 tanks on my modified 04 5sp 32,34,32 and i am at 67k and deffinatly don't baby it.

How the hell can your car do that? Is that mostly highway?

I was saying that the gas gauge should be more correct than it is...it's really far off by my standards. It shouldn't move by what the trip says, it should actually be a measure of how much gas is actually left in the tank.

 

[bgibb68]

How the hell can your car do that? Is that mostly highway?

I was saying that the gas gauge should be more correct than it is...it's really far off by my standards. It shouldn't move by what the trip says, it should actually be a measure of how much gas is actually left in the tank.

he has a 5sp....

 

[tsunami]

How the hell can your car do that? Is that mostly highway?

no highway at all i live in western maine there are no highways here... yes i have a 5sp but even my coworkers get pissed at me, they see the way i drive and how modified my car is and can't believe i regularly get over 30mpg... makes me smile every time i fill up!!!

 

[my3needsaname]

no highway at all i live in western maine there are no highways here... yes i have a 5sp but even my coworkers get pissed at me, they see the way i drive and how modified my car is and can't believe i regularly get over 30mpg... makes me smile every time i fill up!!!

But how do you do it? I get less than 18 regularly with highway. (eek2)

 

[Olestra]

How the hell can your car do that? Is that mostly highway?

I was saying that the gas gauge should be more correct than it is...it's really far off by my standards. It shouldn't move by what the trip says, it should actually be a measure of how much gas is actually left in the tank.

You should see the gas gauges on domestic cars like Pontiac and Dodge.
One minute you have a quarter tank and the next it falls to E.
Start the car back up and it goes back to quarter.
At least our needle is consistent and doesn't bounce back and forth. Once you get used to the gas gauge, that's all you need.
I find the distance to empty computer is fairly reasonable. It will tell you 0kms remaining even though you still have gas left. This is a good thing.

The gauge isn't designed to say, "the gauge reads 3/4 tank so that means my gas tank has exactly 10.875 gallons left in it."

 

[my3needsaname]

You should see the gas gauges on domestic cars like Pontiac and Dodge.
One minute you have a quarter tank and the next it falls to E.
Start the car back up and it goes back to quarter.
At least our needle is consistent and doesn't bounce back and forth. Once you get used to the gas gauge, that's all you need.
I find the distance to empty computer is fairly reasonable. It will tell you 0kms remaining even though you still have gas left. This is a good thing.

The gauge isn't designed to say, "the gauge reads 3/4 tank so that means my gas tank has exactly 10.875 gallons left in it."

My friend has an 07 Pontiac G6 GT and his gauge is really accurate.

I get the gauge bouncing around but only my temp gauge does it...and that was after Mazda replaced my full synthetic Mobil1 10W-30 with crappy synthetic blend 5W-20. (ugh)
I just want my gauge to be closer to what ti actually should be instead of like half a gallon off. I mean half a gallon is a lot of gas...$1.50, 9ish miles, the difference between home and here...lol

 

[evil-98]

should i drive it on full till i hit E and just estimate how much the tank really fills? then just divide it by my total millage on that tank?

the only reason im going off the gauge is because thats what the general consensus would be, and for the sake of comparison.

all i know is i seem to be getting poor MPG and if my gauge is off then i must have some weird size tank because when im almost empty i fill up at about 13+ gallons...

 

[flash75]

Fill the tank, record the miles driven since the last fill and how much gas it takes to fill the tank. Compute mpg with this simple formula.
Miles driven divided by gallons consumed = mpg.
Don't worry too much about what the gauge reads. After you determine mpg with a few fill-ups to average out the mpg you should be able to determine how reliable the fuel gauge is, don't expect it to be accurate through-out the gauge limits.

Clifton

 

[tsunami]

yeah exactly what everyone has been saying divide your miles on that tank by the amount of gallons it took to fill up your tank. a few notes try to always top off your tank the same way either one or two, or no etc... extra clicks that way you will have close to the same only varying a bit from pump to pump if you want to really get anal you could always fill up at the same pump. some people have no problem with that... others find it a pita.

 

[evil-98]

soooo...

i get about 235 mile @ 10.6 gallons w/ 80% highway @ 93 octane = 22mpg

think octane plays a part? i read somewhere that we get better mileage with 89? im going to try it after finishing off this tank but can that be true?

also can get my trip MPG calculator to work, dont know what im doing wrong.

key in, hold CD & AM/FM, turn key to ACC. then i watch the display and it just says hello and operates normally..

yea

 

[tsunami]

deffin don't use 93 use 87 its what your car is supposed to use. i would only use 89 or higher if you have some how advanced your timing or tuned your engine...