Results 1 to 3 of 3

Thread: calculating MPG from OBD-II readins

  1. #1
    Newbie
    Join Date
    Dec 2012
    Location
    Gouda, Netherlands
    Posts
    6

    calculating MPG from OBD-II readins

    Hi,

    In a seperate thread (started in 2006 so I started a new one as the other is probably ignored by now: http://www.mp3car.com/engine-managem...from-obd2.html) I read the following:

    MPG = (14.7 * 6.17 * 454 * VSS * 0.621371) / (3600 * MAF / 100)
    MPG = 710.7 * VSS / MAF

    What I now wonder is: is this calculation for MPG for the average VSS and MAF in an hour?
    E.g. if I have the average MAF value for 12.8 seconds and average VSS in that interval as well, should I then use:

    MPG = (14.7 * 6.17 * 454 * VSS * 0.621371) / (12.8 * MAF / 100)

  2. #2
    licensed to kill - FKA kev000
    Auto Apps:loading...
    tripzero's Avatar
    Join Date
    Aug 2006
    Location
    16.40618, 120.61106
    Posts
    2,560
    This is "instant" mpg. It's not an average over 12.8s (or however fast your reading). It's a snapshot in time.
    Former author of LinuxICE, nghost, nobdy.
    Current author of Automotive Message Broker (AMB).
    Works on Tizen IVI. Does not represent anyone or anything but himself.

  3. #3
    Newbie
    Join Date
    Dec 2012
    Location
    Gouda, Netherlands
    Posts
    6
    Quote Originally Posted by tripzero View Post
    This is "instant" mpg. It's not an average over 12.8s (or however fast your reading). It's a snapshot in time.
    Ah! Ok. That 3600 (in 3600 * maf etc.) got me confused.
    Thanks

Similar Threads

  1. Calculating MPG from VSS and MAF from OBD2
    By maeliosa in forum Engine Management, OBD-II, Engine Diagnostics, etc.
    Replies: 121
    Last Post: 02-25-2014, 09:29 AM
  2. Calculating RMS wattage
    By hutacars in forum Power Supplies
    Replies: 3
    Last Post: 08-10-2009, 03:10 PM
  3. Am I calculating correctly?
    By sonicdevo in forum Newbie
    Replies: 4
    Last Post: 10-02-2006, 01:32 PM
  4. Calculating Amperage
    By 047025n in forum Power Supplies
    Replies: 16
    Last Post: 07-19-2005, 06:17 PM
  5. Calculating Waypoints
    By GRUNT in forum GPS
    Replies: 0
    Last Post: 03-31-2004, 03:41 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •