31mpg HCHII going in for work...fingers crossed

Discussion in 'Honda Hybrids' started by ematzen, Sep 2, 2010.

  1. Harold

    Harold Well-Known Member

    Those are very low FE numbers. What tires are you using and what kind of pressure? You should not have to struggle to achieve 40mpg. I cannot comment on city as I do this so little. H
  2. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    That sort of mileage is not too bad, for stop-and-go short trip city, and infrequent highway. Depends on time of year too. Our last tank, pre-sale, the trip A was sitting around 6.7 liters per 100 km. Wasn't too thrilled with it obvious, but it was getting colder, maybe "winter gas", lots of short trips. This is with a so-so battery tho.
  3. ematzen

    ematzen Well-Known Member

    I actually do mostly freeway driving, sometimes in traffic, sometimes not. Usually around 60-65mph. It is hilly though (southern california). The tires are not original, and are not low-rolling resistance. came that way. I can't justify replacing tires with tread life left on them for a 5% bump in MPG. It's all about the total sustainability picture.

    If I reset the MPG while on the freeway, I can achieve slightly above 40mpg. Don't have any clue how these cars can be EPA rated 40 in the city and 45 on the freeway.

    Parked the car for a week at the airport, and it started right up, without any loss of battery. Big fan of the new battery.

  4. warthog1984

    warthog1984 Well-Known Member

    Get the rpms below where the cam profile switches over and you'll see (~2300 / 56mph for my '03 EX).
  5. Harold

    Harold Well-Known Member

    I drove from home to Dessert Hot Springs Cal. via Hyway 395 and returned via I-5 and when I arrived home my average was 56 mpg. Your tires a probably a big part of it? When I arrived at DHS Cal. I noticed my rear tires bold on top of it . This hurt my mpg some I'm sure as the rear tow was way out. Brought my average up coming home. H
  6. msantos

    msantos Eco Accelerometrist

    Hi Evan;

    Yes, the tires (by not being low-rolling resistance) are certainly part of the boat anchor you are dragging along. However, you can somewhat reduce the boat anchor effect by pumping them up a bit. If this is something you are willing to do then "How high you can go" should be determined by the max tire pressure.on your current tires.
    Oil type and fill levels are typically the second culprit behind poor MPG's. Long overdue wheel alignments are a perennial issue too. The 12V battery issues: I have indeed lost count as to how many times a bad 12V battery was the reason behind all sorts of problems including chronically bad MPG's.

    55-65 MPH are the sweet spot speeds for much higher MPG levels than what you are reporting and many of us have a lot higher MPG averages to report even on hilly topographies. After 4+ years on my 2006, I will achieve 50+ MPG's without any effort and frequently climb into the higher 60's and lower 70's with DWL and SAHM in tow. ;)

    If you are not easily matching even the newer EPA rating then something is likely amiss for sure.


  7. ematzen

    ematzen Well-Known Member

    Thanks for all the responses. I usually keeps the tires inflated to about 42psi. Sidewalls say max is 44psi. I'm always scared of the mass blowout while pumping up. Maybe I'm just a wuss.

    The car is in the shop today for alignment. We'll see how that goes. Will also replace the air filter (it's about time). Other than that, I've done it all. New 12v. battery, new IMA battery, replaced the under-car shields (they were missing when I bought the car), CVT fluid replaced (not sure if that would impact FE). I'm no leadfoot, so it's baffling.

    Oh, the alignment shop told me the front brake pads are on their last life. Car has 54k miles. Caught me by surprise. $280, but I think I'll do it myself.


  8. warthog1984

    warthog1984 Well-Known Member


    What're they made out of, gold? For $50 and 2 hours you could change the pads and fluid yourself.
  9. Harold

    Harold Well-Known Member

    I'm surprised your pads would be about finished with only 54k miles on them. With regen braking and all, I would expect much more life out of them? H
  10. msantos

    msantos Eco Accelerometrist

    Hi all;

    As far as brake wear is concerned we'll agree it depends first and foremost, on how and where the car is driven. For instance:

    1. A car that is driven frequently over shorter distances will wear its pads very aggressively since regen braking is almost non-existent during the earliest warm-stages.
    2. Driving aggressively - or "normally" like most aggressive drivers do :D - is going to put a big bite on the friction brakes. No way around it and we can always tell when a used hybrid has been driven this aggressively by simply looking at how worn the pads & rotors are.
    3. Hilly or mountain like topography will eat through the brakes of any hybrid especially on long descents that fill the pack way too early leaving the friction brakes as the only good way to control the downward speed.

    On the low end, we've seen HCH-II going in for brake pad replacements with merely 28K on the odometer.:eek:

    With this said, the brake pads on my 2006 HCH are almost pristine and even makes a racket a day after a car wash as I never seem to be able to keep the rust out of the brake rotors. ;)


  11. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    Our ex HCHII (still in the family ;))just passed 80,000 kms, and I had a look at the pads while putting on the snows: they're at maybe 4~5mm remaining. Service limit is 1.0 mm, though that's cutting it close. New is 9.5~10.5 mm.
  12. ematzen

    ematzen Well-Known Member

    Yeah, this was a used 2006 HCHII. I don't know how the first 36K were driven. I do know that the battery always had problems, and when it is in the beginning stages of a forced regen, the car relied on the brakes rather than the regenerative braking (for fear of too quickly filling an empty battery?).

    BTW - after alignment, my drive home was 46mpg over 28 miles. Drive to work was 41mpg (a lot of uphill). I was babying it more than usual, but not much more. I purchased the three years of unlimited alignments in order to keep it constant. That may have done the trick.

    Brake pads being changed this Thanksgiving. Any qualms with Napa OEM pads? Or should I go to the dealership to buy them.

  13. warthog1984

    warthog1984 Well-Known Member

    NAPA pads (except the extreme el cheapos) will work just as good as OEM pads. Hawk HPS pads (or similar) work even better if you are willing to trade off more dusting and slightly shorter life for ~15% shorter braking distance.
  14. ematzen

    ematzen Well-Known Member

    Hi Friends - I wanted to give you an update:

    So, battery is working great now, after the replacement. This means that when I start in the morning, I have a charge, and it provides "boost." I suspect I get boost for a longer period of time thanks to the new battery being properly balanced, etc...

    I am not a hyper-miler (though own two hybrids, and am relatively green: I run a sustainability department at a billion dollar company). I want to drive my cars like normal cars. With that being said, I want them to be as efficient as possible. So, after the battery work, I also worked on the brakes and replaced the CVT fluid. I had the brake fluid bled and refilled, and that ended up lowering my MPG. Turns out the rear brakes were dragging. Fixed those by adjusting the hand brake.

    I'm now averaging just under 41mpg for my commute. Lots of hills, pretty fast driving. I'm very happy with that. It rivals my 2008 prius now. I'd love to see better fuel economy, but this is pretty good.

    Next step: when tires wear out, I'll get the Michelin Energy savers. Not sure beyond that. I think I may have done everything I can. Probably time to re-install the solar fans in the trunk. I removed them for the battery work (so the dealer wouldn't get confused).

    So, although I wouldn't buy a Honda Hybrid again, I am finally getting results in my HCH2 I am comfortable with.

  15. msirach

    msirach Well-Known Member

    Glad to hear it is better and it wasn't all the IMA's problem.

    How many miles were on the car?
    Were the pads worn much? A front brake change is rare under 100k.
  16. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    Everytime our HCHII got brake service at our Honda dealer, it came back with parking brake tightened to the point that it was locking at 1~2 clicks. Spec is 8~10 clcks. I became fairly adept at opening up the center console and backing it off, but it begged the question: why was I paying for this?

    Between that and their persistant overfilling of engine oil, I threw in the towel and went back to doing my own basic maintenance. It's somewhat frustrating though: I know they are more skilled and knowledable about our (former) car, and more inside info, service bulletins.
  17. rhwinger

    rhwinger Well-Known Member

    This car is worth a lot more than 41 mpg. Try a couple basic things and you could be a lot happier.
  18. ematzen

    ematzen Well-Known Member

    Front brakes were almost metal on metal. Just over 50K on the car. I bought it used at 36K, so I am not certain its use before I bought it. Pad replacement is simple enough though.

    When I say I'm not a hyper-miler, I am always interested in increasing fuel economy, however, changing my driving habits hasn't changed fuel economy. I certainly don't have a lead foot, and I have tried all the suggestions. I don't know how you guys get 50+, it is impressive.

    Regardless. Glad to see that I am finally getting this car into the shape it should have been in.

  19. ematzen

    ematzen Well-Known Member

    200 miles today, mostly freeway. 47mpg. Never saw those numbers before.

  20. drees

    drees Member

    Looks like it's just about back to normal. Warm temps this past week should help, too.

    I may have missed it - what tires exactly are you running now?

    Also, what dealership did you take your car to? Hoehn? Good to know what dealerships are good should the need arise...

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