I am taking the car into a dealership today. My son drives the car to school which is less than 3 miles away. He drives around town sometimes and is getting less than 14 mpg! I knew he'd been getting less than expected since I was filling it up often, but when we checked what the mpg was on the last fill-up we were amazed! I Googled the problem and found that several other owners of the same type car complaining of the same problem. I must say ours seems to be the worst discrepancy I've seen. I am hoping that the problem can be fixed. I'm guessing it's covered through the Hyundai factory warranty since it seems like an engine/transmission problem. We'll see.

Update from Sep 6, 2017: The dealership found nothing wrong. They said there was a class-action suit against Hyundai for this problem, but I wasn't able to join because they had already closed the suit. It is still pending, but I spoke with a lawyer at Hyundai and he said it would never be settled because Hyundai would just keep repealing. So basically I am out of luck.

The mileage continued to go up and down with no reason why. Then the brakes went out when my son was driving and he hit a brick wall and fence. Thankfully the airbag was deployed, but the car is a total loss. Now we are in the process of finding out why the brakes failed.

The sticker on the window of my 2013 Hyundai Elantra Limited says the MPJ is 28-38. I'm averaging 24.5 on the highway (I'm alone in the car and not hauling anything)! Any idea why this is an industry secret?! Edmunds, Consumer, etc... all ranked this car as one of the most fuel efficient. 24 MPG is fuel efficient for 1990 and not even competitive now. Why don't any of these rating sites warn us of the lie?! Why didn't the dealership warn me of the lie?! This would've been a deal-breaker for me and now I'm stuck with this car! Now I hate the dealer and Hyundai for this - Hope they both reap the benefits of this dishonesty!

Hyundai told me that the mileage would get better when the engine broke in. I have never gotten more than 31 mpg on highway driving. Day in and day out, I average 27.5 mpg. I tried to turn this car in under the Lemon Law, but they brought their lawyers. They wouldn't allow my gas receipts (I recorded gas mileage on every tank of gas). They tested my car and they said it got 41.3 mpg. I guess if you jackup the front wheels, turn off the air conditioning and set cruise control at 30 mph, that may be possible. They got fined $300,000,000 by the government for false mileage claims, but I never got a nickel. I can hardly hear anyone on the phone when I'm driving: they designed it that way to keep people off the cell phones. I will never buy another Hyundai.

Purchased this car for the Great Fuel Mileage. Was unable to get even CLOSE to the 40 (later changed to 38) MPG that the car was supposed to get the best I ever saw was a trip to Vegas at over 250 miles with just my wife and myself in the car. I got a poor 31mpg. Mind you this is 100% highway at 70 mph... while my 16 year Civic gets 362 miles per 9.7 gal on the last fill up. You can do the math.

I feel cheated every single time I get in the car and it upsets me that I settled for this car that can't even get its rated MPG. I had a 2003 Altima that was rated 28 on the highway. That same trip to Vegas? I got 31 out of it? so Why did I downgrade to a smaller car with less power and comfort for the same fuel econ? Just knowing that Hyundai cheated on the EPA test means more about the confidence they put in their cars....

My 2013 auto Elantra (built in S.Korea) with 30000+ miles of driving has averaged an excellent 39mpg with 15% city driving & using 100% ethanol-free gasoline(E0). Top mpg with extra highway driving has been 43mpg. When using E10(10% ethanol), mpg drops to 36 & lower with excess city driving & stop&go traffic.The car is now in the hands of another family member & we purchased a 2016 manual Elantra. MPG is lower, down to 35.5 mpg, but in heavy stop&go traffic, 25% city, & more use of E10. When E0 was used in a trip to the ocean, with stops for pix & beach walking, travel over hills & a bit of stop&go I-5 traffic, we got 46mpg. Elantra only has 130lbs-ft of torque. MPG goes away quickly, with anything but the easiest of featherfooting.

The Elantra MPG is totally a lie. I've driven this car for almost 2 years (half local and half highway), and the average mpg is 25, anything but close to the advertised mpg. During the first few months when I first noticed the problem, I went to the dealer and they told me there's an ease-in period, and once I got 5000 miles, the mpg would pick up. However, that never happens, even with 12000+ miles now.

Before this brand new Elantra, I had a used 2002 Honda Civic. It had much better mpg, 32 on average. So Elantra doesn't save me money at all.

I wanted to love this car - indeed, it looks sleek and pretty from outside. But its performance is disappointing. Very unhappy with the misleading advertising of Hyundai. Will not buy from Hyundai again.

Purchased my Elantra in March of 2013. Loved it. Was getting 35MPG combined city/highway. The following September (2013) over a period of 3 fill-ups, I watched my great gas mileage drop from @350 miles on a 10 gallon fill-up to 335. Okay things happen. The next fill-up it dropped to 320. The next fill-up was down to 290 miles. And it stayed there. After 3 more fill-ups of less than 300 miles per tank, I made an appointment with the dealer. This was a drop off of almost 20%. The dealers answer, "it's winter gas". Really? I bought the car last March in "the winter!" But they insisted winter gas was the cause. I got no satisfaction from the dealer. It's now a year and a half later. I've gotten about half of it back. Getting @ 32MPG now. But I guess my days of 35MPG are gone forever.

Also need to mention that this drop in mileage coincided with an acceleration issue that also couldn't be resolved. But that's another complaint.

My 2013 Hyundai Elantra gets 18-20% less mileage (city/hwy/combined) than originally advertised (I measure mileage by filling the tank up and calculating based off my odometer). I told the dealer and Hyundai Canada and they said there were no reported problems they need to fix and the car is fine. Then they fed me the regular excuses like, your car isn't 'worked in' (I have 30k now), or you don't drive it efficiently.

The class action lawsuit seems to have been cutoff right around my model VIN. Has anyone considered another class action lawsuit for 2013 Hyundai owners that were not covered in the original settlement? Sign me up !

Mileage has been down year to year throughout the lease, which began August 2012. The drop was extreme, however, since we moved and my commute was cut from 25 miles to 7 each way, where in the space of 1 fill-up, my mileage went from about 27 MPG, which itself was inadequate and below par to me, to around 20 mpg (The lying gauge usually indicates 23.5 thereabouts, but it always showed me more than I really got)..

After a wasteful back and forth with the dealer about it, both the service manager and Hyundai itself finally decided that my mileage stinks because I don't drive long enough. So I should maybe take a 15 mile out of the way detour to and from work every day to increase my mileage? What kind of @#$% is that?

I should warm up the car for about 10 minutes before driving? What am I, driving a 1965 Oldsmobile that it has to sit idling cold for an eternity before it will move? I start it up in 70 plus degree weather every morning. It needs to be warmed up? WHAT KIND OF S@%T IS THAT?

So I'm punished by Hyundai for having a blessedly short commute. If you drive only 7 or so miles each way, you can only get about 20 MPG. My old 1986 Grand Marquis could nearly match that.

No solution and no satisfaction. They lied through their teeth about the mileage, period, no discussion!

Very unhappy.