I have one of the first base sonata hybrids sold in central new jersey and still on my first tank of gas with over 600 miles on the car. For $5000K more, I figured I could get my own GPS and I've no use for leather seats (the cloth ones are better looking and there's some cow out there ecstatic that it's still munching grass) or dual moonroofs (I"m 6' 2", so I would rather have more headroom, thanks). I've owned an Insight and Prius and I would never know I was driving a Hybrid--there is no indication in drive feel whatsoever and the body style certainly doesn't scream hybrid (but the nameplate and the head/tail light treatments definitely let others in the know figure it out).
Exterior design--the 3-D tail-lamps and the "dragon eyes" front headlights & chrome; roominess; seat comfort (big difference between hybrid & regular Sonata back seats). The "person" vent control rocks. Easy to use audio & USB. Sound system power & clarity.
Good pick-up when needed! Safety: airbags, stability control, tire pressure monitor, and crash test ratings. The car has a luxury feel. The indigo backlit controls easy on the eyes.
Ride quality good considering the tires. Very quiet inside. Trunk space w/ lithium battery. Musical tones on start/stop. Smart start/entry. I fit in the backseat easily; my kid loves rear pass-through & vent controls.
My one disappointment is highway gas mileage--I've done even amounts of highway and city & averaging just under 34 mpg and have feather-pedaled most of the way. That's about right for city EPA estimates, but below the highway estimates. I'm guessing it's regular use of AC--controlled by the gas engine--in the middle of a heatwave. Redesign next generation AC controlled by electric motor to boost mileage. I'd also like to have nav. as a separate option rather than a package. The radio reception seems weak at times but won't get me to sign up for XM. USB & ipod jack work well. Larger pass-through & glovebox would be great. Turn signal level doesn't always bounce back in place.
Update #6 60K as of this week and so I see it's been awhile since my last update. Changed tires to a different brand at 55K and get much better handling in the car with them than the originals. Mileage may have gone under slightly with them, but I'll take the trade-off. This past winter was exceptionally cold and there was a noticeable decrease in mpg. Now that it's in the 70s again I'm back up to about 32 mpg, which is the highest I've seen since last fall. I'm doing mostly highway @ 65 mph. Anything above that kills the mileage. Highway mileage just isn't good for those of us who use fast lane or ever get stuck in a traffic jam. City is much better than regular Sonata, however. But I will likely buy a used Honda Accord hybrid as my next car (replacing my Insight). Their mileage is consistently high 40s and that's what I had with Prius.
Update #4 I'm almost @ 22.5K and pleased to report I finally had a 40.0 MPG round trip on an all-highway excursion including fairly mountainous terrain. Made the same trip almost a year ago when the car was new but finally figured out how to do it--feather pedaled the whole way, coasted as much as possible, and only used the fan and windows open--no AC. So it IS possible, but you've really got to work at it to make it happen. My city mileage has also improved since the updates and it's consistently 32 or so now. Mix is 34-35, so I'm pretty satisfied with that. I've got the low tire pressure warning on again so next oil change I'll ask to have that fixed for a second time. But now that I've figured out how to get the care to better mileage (after the sensor replacements), I'm pretty pleased.
Update #3 I"m just shy of 18K in mileage. Had the dealer do all the updates and that improved gas mileage by 3-4 mpg. So I'm close to what CR reported now. Tire pressure light went on but tires were fine. Mileage is never calculated accurately on the car, it's always 1-2.5mpg lower when I hand calculate. That's been the only other issue. When I talked to the new service manager, who came from Toyota, we had long discussions about folks who haven't driven hybrids before and the challenges to learning how to drive the Sonata in ways that increase the mileage. He said his customers are all averaging 30-35 mpg with their Sonata hybrids. We've had an unusually warm winter so I don't know how low it would go in super cold weather but most hybrids usually aren't as efficient in winter driving. I've had multiple friends in the car and all agree it's very smooth riding. I've had no problems with acceleration--there's plenty of power when needed but I also don't accelerate heavily unless there's a reason to do so.
Update #2. I"m at @ 12K in terms of mileage now. No problems other than the low tire pressure light comes on but the tires are fine. That should be fixed at 15K service coming up soon. Mileage is now @ 31 mpg with more city than highway driving....only city I'm only getting @ 27-28. Consumer Reports got 33-34. I've driven 3 other hybrids and don't do anything different with this one--I keep ac/heat on low and only as necessary for ac; heat however, well, it's gotta be on when it's cold. We'll see if the 15K service brings up the mileage. I do 65-70 on the highway with some hills and can get it up to 32mpg with half my miles in city. Stop and go kills the mileage unlike any other hybrid I've been in. I dread it and used to love it b/c in other hybrids either the gas engine turns off or it goes on all electric. So Hyundai really missed the boat on the mileage claims, and so did the EPA.
Update #5 30K here and just did the major service. The last tank was 35 mpg, even mix of city and highway but almost no a/c use. That's what tanks (pun intended) the mileage. When I drive conservatively I get better mileage but there are times that its annoying. I could have a much more lead foot in either the Prius or Insight and get better mileage. However, the look and feel and size of the car are plusses so I am ok with the tradeoff. But the engineers need to do auto shutoff for the engine to get higher mpg in stop & go and city driving. No other concerns other than city mileage not what is advertised.
Update.....I've been busy and now have over 6,000 miles on the car. I stand by my initial review. No problems whatsoever so far with the car. I love to drive it. The brakes are a bit mushy when it's wet pavement is the only other minor concern. I"ve done mostly city driving and the mileage has stayed @ 33mpg. I can raise it some on the highway, but I don't think anyone is getting 40 mpg out of this consistently if they are doing
a mix of city and highway. I await Consumer Reports and others who use independent data to verify this.