MPG Underperformance

Discussion in 'VW Jetta hybrid forum' started by Bossless, Aug 3, 2014.

  1. Bossless

    Bossless Member

    Recently Ford and before that Honda Civic had to lower their hybrid MPG ratings and compensate customers for the underperformance of their cars based on advertised EPA mpg ratings.. The Lincoln MKZ hybrid underperformed by 7 mpg and the Ford Fusion hybrid by 5 mpg. According to Consumer Reports tests the Jetta hybrid underperforms by 8 mpg. The average underperformance of 17 owners as reported on fueleconomy.gov is 6 mpg.


    When I first bought my 2013 Jetta hybrid it also underperformed with respect to gas milage. After learning better how to drive it and with careful driving I was able to consistently meet the 45 mpg combined driving rating . That is until the safety recall which I had performed at 8630 miles. The recall changed the transmission synthetic fluid to a mineral based fluid and reprogramed the transmission control software.


    Since then I have not been able to ever achieve the 45 mpg average again even with the same or even more careful driving protocol. 41 to 42 mpg average is the best I can do. I took it to the dealer at 14,961miles. They tested the car and recorded and documented a combined driving mpg of 36.2, even worse than mine. A VW corporate troubleshooter then had the car tested on the interstate at a steady 70 mph for 55 miles and recorded and documented 46.1 mpg. He then declared there was nothing wrong with the car and that it was within specifications. However, that was a highway only driving test and did not indicate the overall mpg performance of the car. Based on my own tests I believe the car underperforms by 3 to 4 mpg combined driving.


    My complaint is that the car I bought is not the same car I drive now due to the recall modifications and that as a result of that I am being penalized with lower gas milage.


    I solicit feedback as to what you think about this situation and if you think there should be compensation. Thanks.
  2. tomo366

    tomo366 Member

    Never since day 1 has the car (Jetta Hybrid) gotten advertised Gas Mileage......Lifetime average is 38.1 best ever was 46.1 and I do not and will not Hyper mile....my Jetta Sportwagen TDI 6 Speed Manual was a fabulous car! But lifetime average was 33.8! I have a 3 mile drive to work.....the reason I sold my Sporatwagen was of potential problems down the road and I needed to sell it then to get my equity out to put down on my Hybrid! I knew the hybrid would not have good resale value......these cars do not sell.....I have been able to find over 200 in the used car market......it is however a good car (Hybrid) but it really is not for everyone,I bought it because I loved the high end options I couldn't get on the TDI .......
    I am going to have to hold onto it for now........no choice.....
    Last edited: Aug 4, 2014
  3. I800C0LLECT

    I800C0LLECT Member

    I think there's an issue with a larger variance for mpg as there's a wider gap for user input. Vehicles like the Prius don't allow too much deviation in driving style while the Jetta does. I think that's crucial. However, I also think it's a hinderance in situations similar to the Op where the owner is familiar with engine performance while VW refuses to acknowledge that because it isn't skewed outside of "normal". I think fuelly would be a great way to showcase how the vehicle is unable to meet previous expectations.

    I had an issue with my TDI where mpg would vary greatly and I'd never know why. But I did notice that it would just almost 10mpg from day to day. The dealership wouldn't acknowledge it because 36mpg per tank was still above VW's stats. In your case it's below advertised. I'm not sure what to say though.

    My only question is did your vehicle receive one of the original updates that seemed to help everybody with mpg? Maybe they decided to zero the vehicle but flashed the older ECU or DSG program?
  4. Bossless

    Bossless Member

    "My only question is did your vehicle receive one of the original updates that seemed to help everybody with mpg? Maybe they decided to zero the vehicle but flashed the older ECU or DSG program?"

    I was told that the update was done before I took delivery. When they did the recall, I am not sure what they did. The description said, "as part of this campaign, only the gearbox control unit is reprogrammed. Do not update other control units." The dealer had my car for over a week because of my fuel milage complaint and they said everything was up to date.
  5. fgbrault

    fgbrault Member

    I am averaging 46mpg over 8800 miles. Initially, on a 3000+ mile round trip from Connecticut to Florida I averaged 43 mpg (driving the speed limit up to about 65 mph on highways). Sine then I have adopted a practice of driving on back roads whenever possible and keeping my speed on highways to around 60 mph or less when traffic in the right lane is going slower or the speed limit is less. I am now averaging 50 mpg in the warm weather and without airconditioning. .
  6. tomo366

    tomo366 Member

    What is wrong with this picture?.......Buy a 30,000 car to drive under the speed limit and create a traffic hazard ?? Not use the A/C this is nuts......And VW doesn't say you have to do these things to get 42 45 48 MPG.......I HATE THE WHOLE PREMISE OF HYPERMILING!!!
    And the fact remains! the only way to get anywhere near the advertised mileage is to HYPERMILE.......People should be after VW just like the people went after Ford and Honda....
    Last edited: Aug 6, 2014
  7. I800C0LLECT

    I800C0LLECT Member

    I try to stay at speed limit or 5mph above if it's rush hour. I've done pretty well with mileage but it certainly doesn't exceed the rating like a diesel would. Hopefully I'm home soon and I can experience some summer weather in the Hybrid :) I'll be adding ceramic tint which might help keep the AC lower. I'm doing it for comfort though...not mpg.

    I'm with Tomo...it doesn't take much to do it and it's not that big of a deal but I'm in a high traffic region so it tends to be unsafe.
  8. DMcDonald

    DMcDonald Member

    It's hard to compare mpgs among different people, living in different parts of the country. I've driven in a variety of conditions, never below the speed limit. With and without ac. AC really only has a significant impact on mpgs in city driving, in my experience. This past weekend I drove up I95 to Maine, two round trips. The first trip was abot 250 miles and I returned 48 mpgs, the second trip was over 320 miles and I got 46 mpgs (hand calculated). More rolling hills on the second trip. Speed between 65-70 mph, with a number of sprints higher when passing. I think the smaller gas engine takes more of a mpg hit with hill climbing, especially compared to a TDI. I don't have an explanation for why the recall would have affected the OP's mpgs. My car did not require that recall. So many factors that are beyond your control can affect mpgs, so I try not to read into some of the variations. The car isn't perfect, but it's quiet, handles great, and is capable of returning excellent mpgs (results will vary).
  9. I800C0LLECT

    I800C0LLECT Member

    In my experience I haven't noticed the a/c hurting mpg's either. I have noticed a significant change in mpg's moving from an altitude of about 3300' with NO humidity to an extremely humid area at sea level. MPG went down noticeably. And it doesn't matter which car or driving style either.
  10. whyknot1

    whyknot1 Member

    I drive 11 miles to work each day. back roads. when there is no traffic and traveling at about 45mph I get about 40 mpg. Going home same route going much much slower I dont get the same mileage sometimes in the low 30's. when I had the car in for 10,000 service I mentioned that but they ran a bunch of tests and found everything to be working fine
  11. tomo366

    tomo366 Member

    The Fact remains unless you a trying really hard! you do not get close to advertised Gas mileage........and you paid big bucks for this car.....
  12. I800C0LLECT

    I800C0LLECT Member

    Before Fuelly became mixed up the Jetta Hybrid was ~39 to 40mpg. I just took a brief look at 2013 model year and if you throw out the single gas engine then the average from all 8 is still roughly 40mpg. It's a 10% variance. I guarantee if they limited the throttle on us we'd easily hit 45mpg. I averaged 40mpg overall through winter. I even received my best tank, 50mpg in winter. I don't try.

    The only reason I'm somewhat defensive is because I do believe these vehicles can achieve much more. There was a hyper-miling review that got into 60+ mpg's. If you really want a steady 45mpg at all times just don't accelerate as much. Install a governor? Learning to judge the traffic in front of you so as not to use the brake as much iasn't that big of a deal and has nothing to do with driving 10mph below speed limit or riding the crown of the road.

    I think it'd be neat if you could choose an ECU program from the factory. You could choose Fuel Economy, Performance, or Blend. You'd be allowed to switch that once for free within the first 20K miles.

    I think it'd open up a lot of people's eyes.
  13. I800C0LLECT

    I800C0LLECT Member

    Now that I think about it...I think this would be a great opportunity for VW. They could roll out the MPG reprogramming for Hybrid's first. The "performance" tune could be later on. It will provide unmatched advertising. If it implements successfully, they could expand the optional fuel efficient tunes to other engines/models.

    That could be leverage for a buyer's mind. They could boast the most efficient vehicle line up quite easily. It might even help swing a new mindset to car buying that would be in their favor, especially with the TDI's.
  14. DMcDonald

    DMcDonald Member

    You're certainly right that these cars can exceed the estimated fuel economy. You don't even have to drive below the speed limit. I have had commutes were the traffic was slow, but kept moving and the MFI read 58 mpgs when I pulled into work. I wound up getting 54 mpgs for the whole tank, hand calculated. The hybrid is like any other car, you can't "drive it like you stole it" and get good fuel economy. That certainly applies to my 2010 Jetta TDI. I would not consider myself a hypermiler by any means, I just use common sense. This is not to say people who don't better mpgs don't have common sense. If you live in areas where traffic is heavy with aggressive drivers, chances are you'll have to accelerate hard and repeatedly to keep up with traffic. That kills mpgs. The other day I was in stop and go traffic, temps in the 90s, ac on. Got 40 mpgs that commute. Not much I can do about it. Your driving conditions/route/technique will dictate the mpgs you get, bottom line.
  15. Bossless

    Bossless Member

    I drive my car carefully and consistently, but not to the extreme. I was happy with my fuel economy before the recall- 45 mpg average. After the recall, with the same type of driving it dropped to 41 mpg average. I tried extra hard to get the milage up, but could never get above 42 mpg average. In a test the dealer could only get 36.2. I just can't understand why the milage dropped. Maybe the recall is the reason. Or, could the dealer have done something improperly that caused the drop? I want my car back the way it was, but am not sure how to get there. The same dealer says the car checks out properly on diagnostics. Would there be any reason that a different dealer would get different results?
  16. I800C0LLECT

    I800C0LLECT Member

    I honestly don't understand what happened either. Ever check your brakes to see if one is dragging? My thoughts were directed more at Tomo than yourself. Sorry if it seemed otherwise. I think you have a legit issue.

    If it was a normal car, in this instance I'd pull the battery for an hour and then see what happens on a full tank. Can't do that here though. I feel like the VW rep was looking at instant MPG as well. That's frustrating. I wonder if all the connections were put back as well. Maybe there's a sensor that needs plugging in somewhere?
  17. Bossless

    Bossless Member

    Yes, I am perplexed. I do have a contact with a VW regional case manager that I talked to once and have now left a callback message so I can ask him about having a different dealer look at it. You would think that if something is unplugged it would show up on the diagnostic. I truly feel that it has something to do with the recall itself or the dealer making some kind of mistake in implementing it.
  18. DMcDonald

    DMcDonald Member

    I agree, we're all stumped. Really makes no sense. Are there any other members here (or on other forums) who have had the same experience as you? I'm sure you're not running around on flat tires, or something. The dragging break cause is good to rule out. I've noticed before when driving slowly with the windows down, close to a wall. You can hear the rubbing. I hope the cause gets figured out. Keep after it.
  19. Bossless

    Bossless Member

    I'm diligent at keeping my tires at 41 psi. Don't think there is a dragging brake, but I will check more closely. I do know that it was never intended that the transmission fluid be changed as a maintenance item. At least it is not spelled out in my manual. Also, they had to send out special tools to change the fluid in the field. I also read in the shop manual that the capacity of 1.9 liters is critical, no more and no less or the transmission will not function properly so it states. So, that means that it must be drained properly or it won't be filled correctly as it is with a dry fill at the factory.

    This seems to be a very sensitive transmission where everything has to be just right, including the software control that was reset, for it to work at its optimum efficiency. So it probably depends on how good the tech was in performing the mod to mineral based fluid and resetting the software. Also, I can see how the transmission would perform most efficiently at highway speeds because it is locked in 7th gear with no shifting taking place. So, the transmission could be off and still not degrade highway efficiency near as much as it would slower speed driving.
  20. fgbrault

    fgbrault Member

    I paid less than $30,000 and I bought it to use less feul, not primarily to save money on fuel. I do very little hypermiling and get better than the advertised milage, at least in the summer. I hypermile only when it is safe. Driving a little under the speed limit in the right lane of a 4 or more lane highway does not create a traffic hazard. On two lane roads I go the speed limit or a couple of MPH above. As to air conditioning, my wife does not like it and I seldom feel I need it. When necessary we do use it. I do almost all of my driving on 2 lane roads at the speed limit or a little above, and when doing so, currently average 50+mpg.

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