One thing to keep in mind is that a car needs to be learned. A Hyundai is not a Toyota and it spans years apart. I own a 2012 sonata hybrid that I am crazy loving. I got a letter from Hyundai that they will compensate my milage difference with a rebate check so really it's not a big deal to me. At least they agreed to pay customers for gas difference. That said, I drive my car like a civil person. I don't race to the next light only to get a red light, I avoid the freeway when possible and take highways with moderate speed limits. I don't tailgate, race, etc. I'm a great driver when it comes to minding my manners behind the wheel. Knowing that, I've had my car 5 months and have 935 miles on it. I have only filled up 2 times so far and I still have 1/4 tank left. I'm doing great milage. In fact when I drive from my home to mums, I get avg 50 mpg. I don't speed or drive crazy as most people do. (I stay in right lanes not to annoy the speeding crowed) I just signed up for fuelly and I'm stoked to post what happens when a person drives proper. I'm getting better mpg then what I thought and what the mpg estimate is so that there proves by driving proper (and legal) you can get that mpg you demand. The car can do it (unless a problem with engine/electronics exist) so that's clear, it's the driver that needs to learn the car. Also, I don't go out of my way to get better milage like coasting or hyper driving, I just obey the speed limits, take routes with proper speed limits, and enjoy the results. Yes, it takes me 2 to 7 minutes more to arrive where I'm going but really, why not slow down. You'll save gas, avoid tickets, and maybe even avoid a crash and your stress will be reduced.
Well you can obviously afford to take your time doing less than 1000 miles on almost half a year. A lot of people do that mileage in a week, a few days perhaps so its a bit naive to assume everyone can adopt those techniques everyday. Time is money, and people need to work, thats why people appear to be in a rush most of the time.
The funny thing is that I discovered that decreasing my peak speed didn't make any obvious difference to my average journey times. I think it was because the roads are so congested that you're only at peak speed briefly, and then you have to brake again for another cluster of cars.
It will probably become more efficient as it breaks in further, maybe a little maybe, but I wouldn't have super high expectations of a big jump. I put 18K miles on my 2011 Hyundai Elantra Limited, and the mpg never really increased over that time significantly. I did about 60/40 mix of highway/city and averaged 29.9 overall. Which is close to the modified EPA estimates and just about at the Fuelly median. But when I looked back over my charts, there was never a noticeable jump at a certain mileage point, it was just pretty consistent. I think the Elantra can easily achieve its highway mileage, but the city mileage is not completely realistic on a regular basis.
The thing with any of these cars, is that the estimated MPGs are in perfectly ideal conditions, and dont reflect reality especially over the length of a year when you factor in weather, ethanol, temps, etc, as well as driving habits.
In the end i switched to a VW TDI Jetta, which gets better than the EPA, but I havent noticed a jump either as it breaks in.
You made a great point though. I think the Fuelly numbers, when I look at my Jetta and at the Elantra, are pretty spot on as far as the bell curve goes with my experiences. I am right at the midpoint on both. I wish i had looked at the Fuelly charts before buying the Elantra, I think I would have had a better and more realistic idea for what to reasonably expect from the car overall.