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Honda Accord Hybrid: 50 MPG City - clone Toyota

Discussion in 'Honda/Acura Hybrids and EVs' started by bwilson4web, Sep 8, 2013.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I'm waiting until the March 2014, EPA test car report with the roll-down drag coefficients. I use them to calculate the drag-power curve at different speeds. What this allows us to do is see how much energy the drive train has to provide between different cars:
    • drag-power curve >> known_model :: the initial C-MAX numbers were wrong and this told the tale
    • drag-power curve ~= known_model :: we can believe the EPA numbers and any differences are drivetrain
    • drag-power curve << known_model :: someone in marketing or engineering is going to get fired!
    The only other place I now that uses the EPA test car, roll-down data is Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com and even there, only a few understand what it means. In fact, it is where I picked up the roll-down coefficients to generate drag-energy curves.

    I expect the Honda Accord Hybrid owners to be busy testing the limits of their vehicles . . . a very good thing. But I suspect none of them have done an MPG vs mph chart . . . yet. That is the gold standard and requires some attention to detail. I could be wrong and would welcome if one of their advocates brought such a chart to share with us.

    The reason I'd like to see their chart is to compare it to the drag-power curve. This would let is see what inflection points exist in that car. These may be natural boundaries where being on one-side, life is good, but being even 5 mph on the other, life is not so good. For example, my 2003, NHW11 Prius:
    [​IMG]
    • 41-44 mph :: something bad happens here, avoid
    • >65 mph :: something bad starts to happen, avoid
    • draining excess oil :: something GOOD happens
    • NHW20 :: very nice at higher and lower speeds than 70 mph
    If someone with a foot in both camps wants to bring some engineering data, I'll be interested in taking a peek but I'm interested, not committed. <grins>

    Bob Wilson
     
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  2. Stevevee

    Stevevee Active Member

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    The comments and results do seem similar. Like myself, I'll bet most on the Honda site are new to hybrids. I picked mine up in late May, and cruised through the summer and fall easily producing great numbers. After that, the weather was the single most negative factor, especially the wind. The difference between car.com results and most everyone else is quite a large difference. Weather does not seem to be a factor.

    Unlike normal ICE vehicles, normal day to day driving conditions seem to have a much great impact on hybrid performance. Wind, Cold, hills. Even with the cold, I have no trouble achieving +40 mpg on a longer drive if it's 60 mph or less. The major change is on my commute, which is incline one way, sometimes windy in a major way, and heat is required. Not unusual that my drive in results in 35 - 38 mpg, and the return trip is 40 or better.

    Another difference between the Prius and the sedans, including the Camry hybrid, is that the engines don't drone on and on, struggling to go up the inclines and larger hills. I guess in the Prius, you'd call that additional Feedback ;)

    Last summer I had no trouble exceeding 44 mpg on long, hilly interstate trips. I didn't baby it, I went 75 mph pretty much the entire way, and back. It would be interesting to guesstimate what I'd get now with the snow tires on and the cold weather, but I have no desire to do another 600 plus mile test trip now.
     
  3. bisco

    bisco cookie crumbler

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    all good points, and on ice cars, you don't think about mpg's or have the readout in front of you at all times. pre hybrid, we new winter mpg's were lower, but you don't contemplate it like we do here!:p
     
  4. frodoz737

    frodoz737 Top Wrench

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    Let's be honest here, most hybrid owners are a little obsessive regarding mpg.

    "Oh my god...what's wrong with my car...I only got 41 mpg. :eek: "
     
  5. Stevevee

    Stevevee Active Member

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    I was always slightly anal about gas mileage, and I've had many cars in my lifetime that got between 35 and sometimes over 40 mpg average. My 2004 Corolla was so consistent, winter/summer, no matter, it got between 36 and 38 all the time. When I beat on it a bit, it would DIVE down to 34/35. The ICE cars for the most part, I've never seen much in the way of a drop in mileage in the winter. The only times were during extensive warm ups, same as any car.

    My Avalon had the mileage readout, and it does make you pay more attention. That car got 30-33 on a trip, generallly averaged 26/28 overall.
     
  6. frodoz737

    frodoz737 Top Wrench

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    Funny...I had a 1985 Honda CRX that matched what I get in my Prius.
     
  7. bisco

    bisco cookie crumbler

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    the winter summer difference is larger because the ice has to run more often in the hybrid to warm up and provide heat.
    but ice cars still have to deal with winter gas and other inefficiencies of cold weather. i can't quantify it, but in our pre hybrid camry's, it was noticeable. most of our driving is local, so the short trips around town are probably more notieable in an ice vehicle than longer highway use.
     
  8. Trollbait

    Trollbait It's a D&D thing

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    To add to that, while a hybrid's ICE might be at operating temperature the traction battery may still need time to warm up to efficient temperatures.

    Also keep in mind the winter hit is in a percentage to efficiency. Even if a hybrid was impacted to the same extant as an ICE car, the percent drop on higher mpgs means a higher whole number one.
     
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  9. john1701a

    john1701a Prius Guru

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    Have you noticed how most of the rest of the population is totally disengaged, not even aware of what MPG their vehicle actually delivers?

    From their perspective, it would indeed be reasonable to use an "obsessive" label for our awareness.

    From our perspective, we show a respective disappointment for their lack of concern.

    I am left in dismay seeing such a large quantity of people simply not interested, claiming MPG in the 30's is good progress. That makes it even more refreshing when new hybrid owners seek out information, asking questions to learn about what actually affects fuel efficiency. That active participation may be interpreted by some as being a little obsessed. We don't see it that way.

    As for identifying "hybrid owners" based on some thread samples and perhaps some random in-person encounters, think about how many their actually are. Of the 102,284 members on this forum, how many actually exhibit the obsession? Most are just quiet owners reading posts. Toyota has sold over 6,000,000 hybrids. How many of them?
     
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  10. cycledrum

    cycledrum PSOCSOASP

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    Television marketing has proclaimed '30 something' MPG as good. They don't even say highway anymore, only 'it gets 31 MPG' , etc...

    Big issue is gasoline is not a big enough expense for a lot of people. I'm guessing that spending 30 or $40 a week on gas doesn't phase a lot of (most?) people.

    Meanwhile we're having 'extreme drought' conditions in CA and a massive high pressure system leaves us with a smoggy haze on the horizon.
     
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  11. bisco

    bisco cookie crumbler

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    all true my friends. time for an increase in the gas tax. anyonehave o'bama's number?:cool:
     
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  12. john1701a

    john1701a Prius Guru

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  13. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I bought a 1966 VW microBus in 1991 and started a mileage log in a composition book. It did not take long before I could tell when I needed to do an oil change, change the plugs, or adjust the valve backlash . . . there was a dip in MPG. Over time, I replaced the distributor going from vacuum advance to centrifugal and the stock exhaust with headers. This was a long, long time before hybrids.

    Bob Wilson
     
  14. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Well I just checked and the EPA has posted the roll-down coefficients for December 2013:
    [​IMG]
    Source: Test Car List Data Files | Cars and Light Trucks | US EPA

    What this means is the Prius c and Honda Accord hybrid have nearly identical drag. Any difference in vehicle mileage traces back to the efficiency of the engine and drivetrain. What surprised me was the Ford Fusion drag pretty much follows the ZVW30 Prius curve.

    For this graph, I used the "HWFE" test results and sorted by the descending "MPG" column and used the row with the highest numbers for each vehicle. The raw, measured, roll-down coefficients are used for the graphs. BTW, these are the CAFE numbers after all of the other analysis:
    • 71.4 MPG - Prius c
    • 70.4 MPG - Honda Accord hybrid
    • 70.2 MPG - Prius hatchback
    • 67.6 MPG - Ford Fusion
    I prefer the raw, roll-down coefficients as the adjusted ones led the C-MAX to report excessively high MPG numbers. The raw coefficients have a truer reading of drag-power requirements.

    Bob Wilson
     
  15. cycledrum

    cycledrum PSOCSOASP

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    Awww, look at Toyota's signature Baby Blue color for the Camry Hybrid - Baby Blue.jpg

    :ROFLMAO:
     

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  16. frodoz737

    frodoz737 Top Wrench

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    Bob, admittedly you have more knowledge, resources and time allocated to research this aspect than I. If you feel inclined, it would be interesting to see the 2014.5 Camry Hybrid added to your model.
     
  17. hill

    hill High Fiber Member

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    wow ..... less than 1/3 of 1% between the two.
    .
     
  18. bwilson4web

    bwilson4web BMW i3 and Model 3

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    See if you can mod a copy of the spreadsheet. I've highlighted the columns with the roll-down coefficients I use. Just cut-and-paste the model and coefficients from the first sheet, the raw EPA data, into the second sheet. It will automatically modify the chart to show what is going on.

    Bob Wilson
     

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  19. Sergiospl

    Sergiospl Senior Member

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  20. pmike

    pmike Member

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    and $7k.