[KoupEsEcks]

The official Kia Motors website says that the gas tank in the 2.4 SX (my car) is 13.7 gallons. This cannot be possible, because no matter how much I fill the tank, I can't even squeeze 200 miles out of it. Most I've ever gotten out of a complete fill-up was 192 miles, and that was only after I literally squeezed so much extra gas into the tank that it was pouring out of the side. So, my question is, is the tank really that small, or is it another problem like the spark plugs? Or the sensor? Thanks in advance.

 

[arinesmith]

Sounds like you are getting crappy gas mileage. If you are only getting 14mpg then you would only get about 200 miles on a tank. You mention how many miles you are going but not how many gallons you are putting in at fill up.

 

[Anthonyc77]

Did you check... your driving? Having a heavy foot can lead too a huge loss in gas mileage. Also do you fill up the second the gas light turns on? Usually companies will leave an extra gallon or 2 still in the tank when the light comes on, for reassurance. Is your driving mostly city? Is there any highway driving? With these answers we can better help you. You very well might have faulty plugs or sensors though.

 

[missourimule]

The official Kia Motors website says that the gas tank in the 2.4 SX (my car) is 13.7 gallons. This cannot be possible, because no matter how much I fill the tank, I can't even squeeze 200 miles out of it. Most I've ever gotten out of a complete fill-up was 192 miles, and that was only after I literally squeezed so much extra gas into the tank that it was pouring out of the side. So, my question is, is the tank really that small, or is it another problem like the spark plugs? Or the sensor? Thanks in advance.

The brochure also says 13.7 gallons. And BTW do not continue to fill the tank after the pump clicks off. You can, and probably already have, damaged the canister system that grabs the fumes to be burnt off later. I know there is a tendency to want to get the last drop of gas into the tank but resist the temptation. It will even out.

You should expect to get about 300 miles from a tank before you have to refill although one should never run out as it could damage the fuel pump which is lubricated by the gasoline. Then you are looking at about a $600+ repair bill. I never let the fuel gauge go below 1/8 of a tank and usually refill when it about 3/8 of a tank.

I'm getting 25.2 mpg overall on my 2011 5 door SX automatic with 2.4 engine after 5,600 miles. The worst gas mileage in all city driving was about 19 mpg. The best about 34.5 mpg in all highway driving.

 

[KoupEsEcks]

Well I know that overfilling could actually have negative effects, that's why I only did it once. But I never let the gas run down all the way. I have no idea why I'm getting such mad mileage, I don't leadfoot. I hardly even depress the pedal. Last time I filled, it said I put in about 11 gallons, but it sure didn't feel like it, because I pressed the TRIP button to see how many miles to empty, and once again it said 192. As I began driving, not even a couple minutes went by before the number started gradually dropping. And it always does that. I don't understand why. I have a Magnaflow muffler and an intake in the car, BUT that couldn't even really be it, because even before I put those things in the gas mileage was still acting up. I've never gotten anything even remotely close to 300 miles out of a tank. The TRIP claims I'm getting anywhere from 16 to 26 MPG everyday, and it literally fluctuates like it's nothing. I'm thinking this is a deeper problem.

By the way, it's a 2.4 SX, and I've LONG since stopped driving tiptronic.

 

[missourimule]

Well I know that overfilling could actually have negative effects, that's why I only did it once. But I never let the gas run down all the way. I have no idea why I'm getting such mad mileage, I don't leadfoot. I hardly even depress the pedal. Last time I filled, it said I put in about 11 gallons, but it sure didn't feel like it, because I pressed the TRIP button to see how many miles to empty, and once again it said 192. As I began driving, not even a couple minutes went by before the number started gradually dropping. And it always does that. I don't understand why. I have a Magnaflow muffler and an intake in the car, BUT that couldn't even really be it, because even before I put those things in the gas mileage was still acting up. I've never gotten anything even remotely close to 300 miles out of a tank. The TRIP claims I'm getting anywhere from 16 to 26 MPG everyday, and it literally fluctuates like it's nothing. I'm thinking this is a deeper problem.

By the way, it's a 2.4 SX, and I've LONG since stopped driving tiptronic.

I'm wondering if you have a computer problem of some kind where it is running in "limp" mode or something like that. I'm not wild about these modifications you did to your car. You will have a problem with getting this fixed under warranty should you press the issue. If it were up to me I would put the stock components in place and then lean on KIA to hook up their computer to see what kind of codes it spits out.

I can post every mpg figure I have had since I purchased my car last November and I get an average of 25.2 mpg, which is somewhat surprising in that I got 26.2 mpg in my 2009 Sonata with the same engine and five speed automatic and was about 350 pounds heavier. It is possible I had more highway mileage figured in, however. With my 2008 Sonata, same engine, I got almost the same fuel mileage. Oddly enough I think the automatic actually gets better fuel mileage. The new six speed transmission is supposed to yield 8% more fuel economy than the previous 5 speed. But I haven't seen it yet.

I'm thinking of working up a fuel mileage spreadsheet sometime to use in Excel or OpenOrg if I can't find one already done somewhere on the internet. This makes it doubly accurate. I'm always dubious about claims of fuel mileage of those who claim certain numbers which seem outlandish. I'm not saying that of you but sometimes people tell me numbers which I know to be ridiculous. And they always use one tank of gasoline and don't keep good records. I do and always have.

I would suggest you start keeping meticulous records beginning today and see exactly what you are getting. You need reliable numbers to show the dealer.

BTW, have you changed the tires, wheels or tire diameter? (wider tires yields less fuel economy)

I just wish people would leave these vehicles alone. Sometimes they are their own worst enemy. (I'm not speaking of you but when I see some of these big or small after market, and very expensive, wheels on cars I just think these people were born with only half a brain. They put thousands of dollars in wheels on these $2 cars.)

 

[Anthonyc77]

because I pressed the TRIP button to see how many miles to empty, and once again it said 192..

Wait are you sure your actually getting 192 miles? According too your ODOMETER? The trip computer can just say whatever, what matters is what your odometer is actually saying...

 

[CreaseKeeper28]

Wait are you sure your actually getting 192 miles? According too your ODOMETER? The trip computer can just say whatever, what matters is what your odometer is actually saying...

Well, I've learned that the "Distance to Empty" computer basically takes the current information. In other words, if you're doing some serious pedal stomping, and your MPG's are down in the teens....when you fill up, it will calculate on that. Then, recalculate once you get back on the road (usually my avg MPG gauge goes blank for a min, then starts counting up as i drive and averages out).

I'm consistently over 300 miles on a tank of gas. I've actually run out twice (stupid me tried to push it, both times). Thank you KIA roadside service!!!!

But sounds like there's something else going on. I'd get it to a dealer, and try logging your MPG's based off your ACTUAL distance, vs gallons put in.

Fill up.....set your trip odometer to 0. Drive. Next fill up....take the miles driven, divide by gallons put in. That's your ACTUAL (non-computer assisted) MPG's.....see your dealer if it's wacky.

 

[Anthonyc77]

Fill up.....set your trip odometer to 0. Drive. Next fill up....take the miles driven, divide by gallons put in. That's your ACTUAL (non-computer assisted) MPG's.....see your dealer if it's wacky.

Do this OP....

 

[AutoItKing]

I never have, never will rely on the trip computer for gas mileage. Every car I've driven gets it about 3 off, usually higher than what I actually got.

I found a very useful app for iOS called Gas Cubby, keeps track of everything for you, just tell it how much gas you put in, and your current odometer reading; and it spits out everything you need to know!