Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Have you recently switched from a luxury sedan to a luxury SUV?
A reporter would like to talk to you; please reach out to [email protected] by 7/25 for more details.
Did you get a great deal? Let us know in the Values & Prices Paid section!
Meet your fellow owners in our Owners Clubs

Hyundai Sonata Hybrid



  • kyrptokyrpto Posts: 216
    This hybrid was engineered for the best possible highway mpg.
    Lots of city driving may keep you from the 35 mpg suggested on the sticker.

    Hypermiler Wayne Gerdes has gotten 60 + mpg on cross country trips in the Sonata and Kia hybrids.
    He loves the Sonatas.

    If you are looking for the very best city mpg, the Toyota based hybrids currently are the best, especially the Prius.
  • acdiiacdii Posts: 753
    If you are looking for the very best city mpg, the Toyota based hybrids currently are the best, especially the Prius.

    Fusion is actually better than the Camry. I know, I had the Camry and now drive the Fusion. Currently getting 43 in city driving 38 overall, and that is only after having it 2 days. Camry was below that. Prius is a smaller car, so it doesn't compare to the Sonata. I had one of those as well. 48 city 65 highway in the Prius, but it isn't in the same class as the FFH, TCH and HSH. It rides like a small car, drives like a small car and handles like a small car. Take the room of the hatchback out of the equation and it falls into the Corolla/Civic class of cars.

    It takes patience to learn the tricks of the Hybrid in order to get the best out of one. There are gauges to help maximize the FE, so study up on how they work and try to drive by those, eventually you will find the cars sweet spot and the MPG will skyrocket. Even a Prius can get 25 MPG if driven wrong.
  • backybacky Twin CitiesPosts: 18,934
    Maybe he was referring to the 2012 Camry hybrid, which has much better FE than the 2011 model--and better EPA ratings than the Fusion hybrid.
  • kyrptokyrpto Posts: 216
    Actually "Toyota based hybrids" include the Fusion as Ford pays fees to Toyota for the hybrid technology in it and the Escape.

    My point is that the Sonata is not the best performing hybrid in urban settings.

    Wayne Gerdes was impressed that the Sonata hybrid was able to power itself electrically at speeds up to 88 mph. He said he thought it would do this going even faster but was afraid to try.

    I have seen our car do this at 75mph with cruise.
    Toyota based hybrids cannot even come close to this but will squeeze out better mpg in city driving.
  • kyrptokyrpto Posts: 216
    two adults on a 400 mile day trip, 90% highway [with 75% of that using cruise control] yielded 42.1 average mpg on the dash display v. 41.12 calculated.

    Total drive time was 5 and a half hours with an average speed of 57 mph.
    AC on for last 200 miles.

    Drove thru the Virginia Piedmont till we almost reached the coastal plain; rolling hills and flats!
    One of the better segments (distance to empty @ fill up was right around 200 miles) we’ve done.
    With just over 7,500 miles, new NVLD, software flashes/upgrades done, and 2nd oil change (synthetic blend) @ 7K, this is encouraging.
  • kyrptokyrpto Posts: 216
    in the last post should have been just under 7 hours.
  • acdiiacdii Posts: 753
    edited September 2011
    Actually "Toyota based hybrids" include the Fusion as Ford pays fees to Toyota for the hybrid technology in it and the Escape.

    Not true.

    "The reality is that Ford independently developed its own hybrid system at the same time Toyota was doing its own. The basic architecture of both systems is the same and both are based on the concepts developed and patented by TRW engineers in the late 1960s. When Ford introduced the Escape Hybrid, Toyota went after the Blue Oval for infringing on its patents. Ford had patents of its own on the technology that Toyota was using. Eventually, the two companies reached a cross-licensing agreement that gives both companies the right to build their own systems. Such cross-licensing agreements are common in these kinds of cases, but Ford did not use the Toyota hybrid system. The only other company that uses Toyota's system is Nissan for its Altima hybrid, and they actually buy hardware from Toyota. We continue deconstructing Reynolds' arguments after the jump"

    link title

    It is similar to the Synergy drive, but Ford does not pay fees to Toyota. The Fusion is a better system than the Toyota. I should know, I drove the Prius and Camry for quite some time and now drive the Fusion, and get better economy than the Camry. Best on EP in the Toyota is 42 MPH, the fusion is 45 MPH. Makes a difference in city driving.

    It does surprise me though regarding the Sonata being more highway than city efficient. Most driving occurs in city driving, even out in rural areas, you still do a lot of stopping. Heck the Prius is rated low on the Highway, but I got 65 MPG in it, even though it is designed for city driving. Puzzling.
  • I believe the specifics are that Ford 'gave' Toyota diesel engine technology while Toyota 'gave' Ford hybrid technology. I think comparison of the Fusion Hybrid to Camry Hybrid is not fair. The Camry hybrid came out first and has essentially been unchanged whereas the Fusion hybrid came significantly later I think. For example, the new 2012 Camry is far better than the Fusion. I don't think it speaks to Toyota hybrid vs Ford hybrid.

    I disagree with the comment that most driving is city driving though. Some people do a lot of highway driving and the highway testing doesn't mean that they don't stop; it just is less stop and go than the city test method. I used to drive a 2010 prius, got 48-56mpg no matter how I drove it although I did see it drop when I consistently drove above 55mph. Sonata we can see a significant difference, if I drive my normal highway routes I can do above 40mpg full tanks, if I do a lot of city driving or if I get a lot of traffic, it goes down to about 37mpg.

    The two systems are fundamentally different; Toyota/Ford/Nissan uses 2 electric motors geared together; you can run the main electric motor to very high RPM even at low speeds to get huge torques in the city. Sonata (and Honda) uses a far simpler method whereby the engine is coupled to the electric motor which is coupled to the transmission. Therefore we can't get the incredible gearing ratios on the electric motor that the Toyota/Ford/Nissans can but we can achieve far higher vehicle speeds on electric alone. Hyundai adds a clutch between the electric and engine to allow pure electric drive. I read somewhere that Toyota actually wanted to do this method when they were making their Synergy drive but the controls systems back then for the clutch was insufficient to get a smooth ride. The simpler method Hyundai uses is theoretically more efficient.
  • kyrptokyrpto Posts: 216
    Thanks for the correction.

    Both Toyota and Ford are using first generation hybrid technology.
    Nickle hydride batteries and droning CVTs.
    It's relatively inexpensive and dependable (except for the 1st Highlander Hybrids).

    Hyundai spent a boatload developing their own hybrid system which was designed and advertised to get better mpg on the highway.
    Best "city" option may be the just released Prius plug in, the first Toyota - Lexus - Ford hybrid with lithium batteries.
  • acdiiacdii Posts: 753
    I think they are heading in the right direction, but I also think their sales will suffer compared to the other hybrids getting higher city MPG where it counts the most.

    As for the LiPo cells they use, I sure hope they gave a lot of thought to fire prevention with their packs. A short can cause a Lipo to burst into flames, and they are hot burners too. They also tend to swell when they get hot, so they need to be kept cool, but also suffer in cold weather moreso than NiMh do. The charge on them must be kept above a certain voltage and below a certain voltage, or the cells will be killed. On a Lipo, they will go down fast if not properly charged/discharged. I have some 1 cell 120mah packs for my ultra micro planes, and before I knew it, a few of them died due to poor charging practices. I had kept them topped off without using them and they eventually lost capacity. One I totally destroyed from a crash, it swelled to 4 times it's size and thankfully ran out of energy before it got hot enough to burn. Another I killed by discharging it past its fail point, and no longer holds a charge.

    Fingers crossed the Hyundai system keeps track of all that so the packs last a long time.
  • kyrptokyrpto Posts: 216
    Don’t think heat is a problem.
    Formula 1 cars have used Lithium batteries for their KERS for years.

    The introduction of the Kinetic Energy Recovery System that will eventually make every future Formula One race car a hybrid began in ’09.
    F1 teams may use KERS to draw 60 Kw from the rear axle, store that energy and reuse it by pushing a 'boost' button. The system uses regeneration to collect and store energy during braking and allows the drivers to use 60 Kw (82 hp) for 6.6 seconds per lap.

    Also included in the system is a KERS control unit. The battery pack is mounted at the bottom of the fuel cell and in the case of Ferrari is supplied by French Li-ion battery maker Saft.

    The Sonata Hybrid has been the #2 selling hybrid - behind the Prius - all summer.
    A lot of people must be looking for a “highway” hybrid.
  • kyrptokyrpto Posts: 216
    Yep, I just figure that with all these F1 race cars in such a high heat environment, sometimes even ‘reckin’ and never a mention of a Lithium battery pac doing anything abnormal, us civilian hybrid drivers are probably safe.

    I remember early in the Toyota’s hybrid rollout, and especially after the Highlander Hybrids were introduced, when rumors of rescue personnel being killed by hybrid components were common. The info about the Hyundai battery pacs is reminiscent of that misinformation.

    A Li-Polymer type battery is used for the Sonata Hybrid. The basic function of the battery system is to store, in chemical form, electric energy obtained either from the engine or regeneration and supply the stored energy as needed. Additionally, it has to manage input and output power based on the state-of-charge (SOC). The BMS (battery management system) performs accurate estimations of battery status and controls the temperature appropriately.

    Compared to conventional NiMH batteries for hybrids, the Li-Polymer type battery of the Sonata Hybrid has a better performance in the power/energy density by weight and volume, self-discharge rate, life cycle, cold weather characteristics, SOC estimation etc. -7&issueKey=2&volumeKey=2011&smart42SID=s292et2tk0rsnjgi81nqp0c9r3&smart42SID=s2- 92et2tk0rsnjgi81nqp0c9r3
  • kyrptokyrpto Posts: 216
    Hmmmmm . . . . . .
    the just introduced Chevy Volt, the new Honda Civic and the new Infiniti M are all using Lithium batteries.
  • acdiiacdii Posts: 753
    LiPo's are great forms of energy storage, no doubt about it and I am glad to see them being used now in greater quantities. Knowing what I do about them though, does leave that question in the back of my mind, did they do everything they could to prevent a failure from a short, or a failure of the charging system that could cause an overcharge.

    Here is a video, I hope I never see this happen with one of my RC packs.
    overcharge failure
  • Bought the Hybrid today and drove 78 miles to Fayettville,N,C, to pick up.. from Cary.. Paid $500 over invoice.. Drove 79 miles home and got 44.5 MPG... Kept my eyes glued on the ECO MODE.. Look to have a great Hypermiler experience.. IE Coming in my development downhill and leaving on flat ground... I was doing 70 mph in ECO MODE on Highway !! JG
  • Going to put either 17 or 18 in Michelins and rims on in the am after purchase today !! Any thoughts ??? Hanhooks 16 in standard on my Hybrid....
  • kyrptokyrpto Posts: 216
    Just make sure they are low rolling resistance tires.
  • Michelin Primacy MXV4... 225/55/17 H rated..
  • vinnygvinnyg N.Y.Posts: 77
    These are the latest updates for the Hybrid and some for the regular Sonata as well. Anyone experiencing low mileage, driveability issues, or first start up of the day jerkiness may find some relief by having these updates performed at the dealership.
    Be kind to the people you meet on the way up, because you're going to meet the same people on the way down.
  • I have 11,500 on my premium Sonata Hybrid and loved it up until this past Sunday when the entire system shut down while going 65 mph on a major highway by Baltimore. No computer=NO BRAKES and very hard steering. The car shut itself down while moving!!! I then sat on hold with Hyundai roadside assistance answering way too many automated questions. In the meantime I tried to re-start the vehicle. It started and ran fine after that but the incident on the highway has me very skeptical. Ever since i bought the vehicle in May it has had intermittent error messages when I try to start it. Any thoughts?
  • kyrptokyrpto Posts: 216
    On the other Hyundai forum you posted on earlier there is at least one Hyundai tech (posting as sbr711) and another Hyundai employee (Car Tech Dude) who may be able to help.
    Much more info there.
    Especially from CTDude.

    Have you had the October updates done yet?
    They may solve all your issues as has happened to several other hybrid owners.
  • We are also having terrible problems with our Sonata Blue. We experience initial deceleration when we try to accelerate on the highway, terrible mileage, repeated idiot warning lights and one time, the engine crashed and turned itself off while traveling on the highway. We are getting lousy gas mileage -- very problematic for a hybrid car.

    We did the recall repair, which was supposed to take care of everything. It did not. Now, our local dealership says we need to take it up with Hyundai directly.

    Have you gotten any relief?

  • kyrptokyrpto Posts: 216
    Post #140 by Vinny G has a link where you can get in contact with an engineer who has helped several other hybrid owners resolve issues. I haven't seen anyone posting here with anywhere near the knowledge about Sonata hybrids as "Car Tech Dude."
  • vinnygvinnyg N.Y.Posts: 77
    edited November 2011
    Don't fret, I was having charging system shutdowns and the warning lights as well. Car Tech Dude on the other forum is involved with the powertrain issues and will private message you to find out what your issues are and contact your dealer and direct them on what to do next. In my case, an engineer was sent out to rebuild the software, then all the updates were applied, and the car is running perfectly now. Here is a link to the site so you can set up an account and private message him: - html
    Good luck.
    P.S.: This is a link to my video of the charging system occurrence which I posted on Youtube a while ago, but I must stress that I have NOT had a problem since it has been repaired and this video will only show you what I experienced prior to the repair and may aid you in explaining it to your dealer or tech working on the car. I know my service manager said it helped him so hopefully it can assist you or anyone else coming here to seek assistance.
    Be kind to the people you meet on the way up, because you're going to meet the same people on the way down.
  • Has anybody had any issues with Allignment on their 2011 hybrid?? I have had my car in the shop 4x already since May and Hyundai has not been able to fix the problem. Only pulls really hard to the left when traveling 65mph+. Hyundai tells me that the hybrid is very sensitive to road conditions and if your in the left lane it will pull left. I'm not buying this it pulls left in any lane I'm in. Please respond if anyone else has noticed this issue.
  • You don't seem to be aware of the "left pull" debacle involving 2011 Sonata's especially, it seemed, the turbo version but some GLS, Limited and SE models as well. I followed the posts with interest because I was considering buying a 2011 but this deterred me. Hyundai seemed to have had no clue what the cause was early on and issued a series of revised specs. for front end alignment and that MAY have worked for some owners to some degree but the bitching went on. Then Hyundai tried other possible fixes and the problem went on and on until many owners with affected cars went to arbitration and Hyundai actually might have bought cars back. Anyhow, be aware this problem did not affect all cars, just a relatively small number. They (Hyundai) eventually found "the fix" which appeared to be revised front strut assemblies and incorporated them into regular production for 2012 Sonatas and are retro-fitting them to earlier affected (2011) cars. The furor appears to have died down and I ended up buying a 2012 SE which exibits no pull whatever. Bottom line..the nonsense your particular dealer is feeding you about Hybrids being sensitive to road conditions is just that...nonsense. All Hyundai dealers SHOULD be clued in as to what caused this and what the fix is by now. As I said I did not know hybrids were subject to this condition but why not the suspension is probably the same or at least similar enough to the non hybrid versions to be affected as well. I believe, no, I know, a TSB was issued by Hyundai outlining the final cause and fix for this and although I do not know its number (others here may be able to help in that regard). See if, once armed with the information, the dealers menmory is jogged and have it implemented. Don't take the "sensitivity" statement as valid.
  • vinnygvinnyg N.Y.Posts: 77
    edited November 2011
    New Campaign from Hyundai Forum:

    There is a new campaign TI2 and everyone on this site for this issue should return to dealer to get it done it is an important improvement for this issue.

    TSB is 01-11-049 and it is entitled HEV HPCU Interlock Circuit Connector Installation.

    It replaces 2 high voltage connectors at the HPCU to make sure they have robust connection.

    Along with the TG5 Multi-ECU Update that most of you probably have it provides the complete improvement to prevent this issue.

    Sorry another trip to dealer but all this took allot of investigation and piecing things together to finally arrive at the best combination of solution which now you will have with the TG5 and TI2 campaign updates.
    Be kind to the people you meet on the way up, because you're going to meet the same people on the way down.
  • vinnygvinnyg N.Y.Posts: 77
    Be kind to the people you meet on the way up, because you're going to meet the same people on the way down.
  • Thank you for your help. I had no idea this was an issue. Dealership acting like they have never had this issue brought to their attention by anyone else. If anyone has any other info on this situation please forward to me.
  • vinnygvinnyg N.Y.Posts: 77
    edited November 2011
    You're welcome. Glad that helped you. You may also want to read this article as well: -

    You should also sign up on Hyundai's service page to get all the latest information regarding your vehicle:

    Good luck.
    Be kind to the people you meet on the way up, because you're going to meet the same people on the way down.
Sign In or Register to comment.