// 05 HCH MPG decrease
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  1. #1
    Junior Member
    Join Date
    Jul 2008

    05 HCH MPG decrease

    My wife has a 05 Civic Hybrid that we bought new. It has had all of its scheduled maintenance performed at the same dealership. For the last three and a half years it has been getting constantly around 43 MPG. A few months ago it dropped to around 35 MPG so we contacted the dealership and they said to bring it in and they would check it out. They said there was a software upgrade that needed to be done. A month after the upgrade was done the MPG has now dropped to 30. We contacted the dealership again and they had us bring it back in.

    We go to pick up the car last night and the service manager came out to talk to us. He says I plugged in the computer and there are no trouble codes so there is nothing wrong with your car. What kind of lame mechanic work is that?

    He goes on to say that the software upgrade they performed was probably giving us a more accurate MPG reading than before. So the previous software made everyone think that these cars were getting excellent mileage and they all ran out and to buy one just to be told later that they really dont get any better MPG than a standard Civic?

    Then he asked if we had recently replaced the tires and we said we had about 6 month ago. He said that was probably a big factor because the tires they put on the car are three time more expensive than the one we had put on because they are more energy efficient and this could cause our MPG to decrease.

    In the end he pretty much said sorry for ya, nothing I can do. What should I do now? Should I call the Honda service number even though they are just going to call the service tech and have him tell them there is nothing wrong? Should I take it to another Honda dealership and get a second opinion?

  2. #2

    Definitely take it to

    Definitely take it to another dealer. This loser doesn't have a clue what he's talking about. Calling the Honda customer service number (not your dealer) at:
    (800) 999-1009

    Mailing Address
    American Honda Motor Co., Inc.
    Honda Automobile Customer Service
    1919 Torrance Boulevard
    Mail Stop: 500 - 2N - 7D
    Torrance, CA 90501-2746

    Also, you should cross post this under the HCH in the cars section of this forum to get more HCH experienced help.

  3. #3
    Junior Member
    Join Date
    Oct 2008

    Did you get your MPG back up

    Did you get your MPG back up to where it was?

    I have a similar issue with my 05 Civic Hybrid. I changed the tires and saw a huge drop in MPG.


  4. #4

    I don't know that the

    I don't know that the original tires on your car would 3 times more expensive than your replacements, more likely on par.

    Fuel economy definitely is one criteria when Honda chooses tires for all their vehicles, and likely the foremost consideration with the Civic Hybrid. They want a good mileage rating, it helps sell cars.

    It is very likely that your new tires have more rolling resistance than the originals. If it's any consolation, they probably have better traction as well.

    What pressure are they at? Try raising the pressure. If the max psi on the tire wall says 44 (for example), try 40~42 psi. If you then take the car in for service, be sure to ask them to leave the tire pressures alone: otherwise they will more than likely bleed it back down to spec.

    Also, look for other mpg culprits:

    One thing we discovered recently (don't know why it took me so long to wake up), our dealership was consistantly overfilling the oil at changes on our 2006 HCHII, by 0.8 liters (putting 4.0 liters in when the spec was 3.2). Too high engine oil level can create drag, the crankshaft is dipping down into the reservoir more, splashing, losing momentum. It can also be detrimental to seals and venting systems.

    Also, how many clicks does your parking brake take to lock up? The spec. is 8~10 to fully locked, for the '06 HCHII. Your's is very likely similar. Everytime the dealer does our brakes they set the parking brake to lock at 2~3 clicks, and I in turn back it off. The adjuster nut is buried inside the centre console. I suspect they don't actually touch this, but the tightening is the byproduct of their servicing the self-adjuster mechanism at the drum brakes. I'm still a little fuzzy on this whole issue, though.

    Also, our mileage always deteriorates in winter, but that doesn't seem to be your issue, with your posting in July. Spring going into summer is the time of the year when your mileage should be *improving*. The car's computer is monitoring ambient temp's and adjusting behaviors accordingly. I notice things like AutoStop, for instance, take a lot longer start working, when the outside temps drop.

    Hmm: judging from what I've mentioned above, maybe one simply way to improve mileage is to avoid the dealership for service

    Seriously, I think it does help to at least learn what you can, and there's multiple benefits in doing some of the simpler service items yourself. Oil changes are a good candidate. The one issue I found with our HCHII was getting the car safely up high enough to swing down the plastic undershield. It is doable, but you really need to put the whole car up on jack stands. I would use Honda parts, save all receipts, log the what/when/kilometers, *and* keeping the dealership "in the loop" on what you've done.

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