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eco savings fuel cost (premium vs regular fuel)

Discussion in 'Prius c Audio and Electronics' started by Tunget, Mar 1, 2013.

  1. Tunget

    Tunget New Member

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    2012 Prius c
    Model:
    Three
    Is there only one setting for fuel cost? When comparing the c to my other vehicle (BMW M Roadster) it doesn't really give me the correct savings because the BMW uses Premium at a greater fuel cost. Regular 3.89 vs. Premium 4.30

    When you set the fuel cost in the eco savings menu, it also sets the prius c to that same fuel cost. Is there a way to set 2 different fuel cost for the 2 vehicles being compared?

    (If not, I'm thinking about writing a data conversion program that would make up the difference between the 2 cars. Input the fuel cost of regular and premium and then get a new fuel cost number to input into the eco savings menu that covers the difference. It may be something crazy like $80 a gallon though.)

    I would like to get a savings number that takes into account that the fuel for both vehicles is a different cost. (I know I can do this manually on a computer.) ...I'd rather just have the car do it automatically. ...otherwise the savings number means nothing to me.
     
  2. vdefender

    vdefender Junior Member

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    Two
    It's really not that difficult to do it manually anytime you want to know your real savings.

    Each time you fill up, take note of the price of premium and regular. Update the prius to the cost of the regular gas you put in.

    Premium cost = P
    Regular cost = r
    Prius computer savings = S
    Actual Savings(price adjusted) = A

    (P / r) * S = A

    Which given your pricing example and lets say the prius says you saved $56.32.

    (4.30 / 3.89) * 56.32 = $62.25 Actual savings price adjusted.

    Now if you buy gas from the same gas station, usually the difference between regular and premium is the same. So you can take (4.30/3.89) = 1.1056 and just remember that number. Then each time you want to know your price adjusted saving just multiply that with what the prius says using your phone.
     
  3. Tunget

    Tunget New Member

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    Yeah, Like I said, I know I can do it manually. (I just don't want to when the car should be doing it for me.)

    Thanks though...the equation might be helpful for other people with the same issue.

    I guess I could set up a little program or even just a simple spreadsheet to keep track. ...just keep it in google docs so it's accessible with my phone. (...and almost pointless over time, because I already calculated the savings based on different inputs over a 6 year period before I even bought the car. I guess you could say that it compelled me to buy it.)

    It just seems like an obvious oversight on the programming. ...and very simple to update if they wanted to. Does Toyota ever update their systems? They should be able to just using a phone for the data through the usb port.

    Otherwise....what do you think this system is programmed in? ...and can we hack the code ourselves? It seems like it could have been done simply with Python or Java or even Lisp. It's just data driving a GUI with control flows based on whatever button is pushed. (...probably void any warranty though.)
     
  4. vdefender

    vdefender Junior Member

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    I'm not really sure what kind of hardware / software system they use. It would be fun to find out and get ahold of the code. But the unfortunate part about it is most likely its a proprietary Toyota OS, which was probably written in low level machine code, and even if the memory could be accessed it would be binary compiled code not nicely formatted C that could be read and altered. But who knows!?
     
  5. Tunget

    Tunget New Member

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    I wouldn't think it would be proprietary because that would be more costly, plus there are a number of existing programming languages that can do this. (...but this is Japan, so who knows.) Plus it's just basic stuff they are doing, nothing top secret. The code wouldn't have been written in machine code but you are right that it is stored as compiled code. (Unless it is just .py files, which would explain the lag in some areas.) ...but even in that case, java can be easily backward engineered to reveal the source code using even free software like cavaj.

    The memory should be accessible because at some point the program had to be loaded into it. If you can load it in, you should be able to copy it out, modify it, and reload it.

    What is most likely proprietary is the plug to access the memory or even the memory unit itself. I doubt if there is a MicroSD card or a flash drive that holds it. ...but who knows, it would be cheaper.

    It might be cool to have a car with open source software that people could work on together to make better.
     
  6. Rob.au

    Rob.au Active Member

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    To me that sounds horrifying, but each to their own. :)

    I'm not against open source... but in my car, no thanks.
     
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  7. ztanos

    ztanos All-around Geek!

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    If Microsoft made Cars

    1. A particular model year of car wouldn't be available until AFTER that year, instead of before.

    2. Every time they repainted the lines on the road, you'd have to buy a new car.

    3. Occasionally your car would just die for no reason, you'd have to restart it. For some strange reason, you would just accept this.

    4. You could only have one person at a time in your car, unless you bought a car '95 or a car NT, but then you'd have to buy more seats.

    5. You would be constantly pressured to upgrade your car. Wait a sec, it's that way NOW!

    6. Sun Motorsystems would make a car that was solar powered, twice as reliable, 5 times as fast, but only ran on 5% of the roads.

    7. The oil, alternator, gas, engine warning lights would be replaced with a single "General Car Fault" warning light.

    8. People would get excited about the "new" features in Microsoft cars, forgetting completely that they had been available in other brands for years.

    9. We would still be waiting on the "6000 sux 58'" model to come out.

    10. We'd all have to switch to Microsoft Gas (tm).

    11. Lee Iacocca would be hired-on as Bill G.'s chauffeur.

    12. The US government would be GETTING subsidies from an automaker, instead of giving them.

    13. New seats will force everyone to have the same size nice person.

    14. Ford, General Motors and Chrysler would all be complaining because Microsoft was putting a radio in all its models.
     
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