Page 2 of 12 FirstFirst 123456789101112 LastLast
Results 11 to 20 of 114

Thread: Micra speedometer shows faster than it's really going

  1. #11
    Senior Member aftica's Avatar
    Join Date
    May 2014
    Posts
    370
    Thanks
    0
    Thanked 67 Times in 47 Posts
    Quote Originally Posted by MetroMPG View Post
    But since the output to the odo/speedo comes from the ECU (no more direct mechanical drive speedo/odo cables), it would be easy to add a correction factor to one or the other. Just curious.
    Ah, I didn't know they could be calibrated separately... anyway, I think they both need some tuning. (trucks are blowing by me and my commute is ''longer''! )


    Ten Grand Tin Can

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S manual: 5.3 L/100 km ... 53.2 mpg (Imp) ... 18.8 km/L ... 44.3 mpg (US) ...


  2. #12
    Junior Member
    Join Date
    Feb 2014
    Location
    Chilliwack B.C. Canada
    Posts
    13
    Garage empty: add car
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Maybe its Nissan's way of saying slow down live longer .. and save gas

  3. #13
    Senior Member Antruby's Avatar
    Join Date
    Apr 2014
    Location
    Wellandport Ontario
    Posts
    129
    Thanks
    19
    Thanked 16 Times in 16 Posts
    Quote Originally Posted by AlphaMicra View Post
    I did a test today, I compared my Micra's speedometer with that of my GPS. I was surprised to find it off by 5 KPH.



    It seems to be less off at lower speeds, and more off at higher speeds.

    After that, I decided to reset my trip counter in both the Micra and my GPS at the same time. After the Micra showed 80.4km of travel, the GPS showed 78.06km of travel.

    Has anyone else noticed this?
    This may sound crazy but check the front tire pressure. I had Bruce raise mine to 37 lbs. cold from 35 lbs. from the dealer. I feel the fronts should be more as it has the weight of the running gear and driver (Some times pass.) Made a difference in the Speedo/GPS reading. Speedo is higher now.
    Last edited by Antruby; 06-15-2014 at 11:19 AM.
    Antruby (Rose) My blog is Antruby.com
    I love this fantastic Micra. Love the ride. Love the colour. Love the size. Love the light in the hatchback. Love the bluetooth. Love the fact the rear windows go all the way down. Love the headlights that someone took time to aim in the right places. Love the fuel filler being on the drivers side. Love that the fuel filler door locks from inside the car. (No need for key.) Love the stainless steel license bolts put on by dealer.

  4. #14
    Senior Member AlphaMicra's Avatar
    Join Date
    Mar 2014
    Location
    Oshawa, Ontario
    Posts
    1,037
    Thanks
    114
    Thanked 245 Times in 174 Posts
    Quote Originally Posted by Antruby View Post
    This may sound crazy but check the front tire pressure. I had Bruce raise mine to 37 lbs. cold from 35 lbs. from the dealer. I feel the fronts should be more as it has the weight of the running gear and driver (Some times pass.) Made a difference in the Speedo/GPS reading. Speedo is higher now.
    Thanks, I'll try that. It seems a little odd, because the sticker inside the driver's door specifies 33 psi for the 15" tires, and 37 would put them at 4 psi over manufacturer's spec.

    In our culture obsessed with absurd excess, the Nissan Micra is my counterculture car of choice.
    Be sure to visit my blog at mymicra.com!

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra SV manual: 6.4 L/100 km ... 44.3 mpg (Imp) ... 15.7 km/L ... 36.9 mpg (US) ...


  5. #15
    Senior Member aftica's Avatar
    Join Date
    May 2014
    Posts
    370
    Thanks
    0
    Thanked 67 Times in 47 Posts
    Quote Originally Posted by AlphaMicra View Post
    Thanks, I'll try that. It seems a little odd, because the sticker inside the driver's door specifies 33 psi for the 15" tires, and 37 would put them at 4 psi over manufacturer's spec.
    Going with more pressure should theoretically make for a slightly larger tire diameter, which would give you more speed and more km's than indicated. I can't really see a few lbs making that much difference though.
    I usually run the tire mfg's max pressure, which on my base model car is 40psi.
    All of which reminds me that I have not checked the tire pressure yet!
    Ten Grand Tin Can

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S manual: 5.3 L/100 km ... 53.2 mpg (Imp) ... 18.8 km/L ... 44.3 mpg (US) ...


  6. #16
    Administrator Daox's Avatar
    Join Date
    Feb 2014
    Posts
    751
    Garage empty: add car
    Thanks
    202
    Thanked 83 Times in 62 Posts
    Steel belted radial tires do not balloon with pressure really (I'm sure they move a tiny bit, but its not noticable), the steel belting holds their form and diameter very well. Older bias ply tires certainly did balloon out. Tire pressure shouldn't have an effect on tire diameter / odometer / speed readings.

  7. #17
    Senior Member aftica's Avatar
    Join Date
    May 2014
    Posts
    370
    Thanks
    0
    Thanked 67 Times in 47 Posts
    Quote Originally Posted by Daox View Post
    Steel belted radial tires do not balloon with pressure really (I'm sure they move a tiny bit, but its not noticable), the steel belting holds their form and diameter very well. Older bias ply tires certainly did balloon out. Tire pressure shouldn't have an effect on tire diameter / odometer / speed readings.
    Yeah, i'm having a hard time with Antruby's claim also. It is very easy to get any tire to ''grow'' with added pressure, it's just that within the acceptable range I doubt there is a noticeable difference, unless it was tracked over many, many kilometres. There might be something else that is influencing her experience...do GPS numbers vary at all?
    Ten Grand Tin Can

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S manual: 5.3 L/100 km ... 53.2 mpg (Imp) ... 18.8 km/L ... 44.3 mpg (US) ...


  8. #18
    Member
    Join Date
    Jun 2014
    Posts
    38
    Garage empty: add car
    Thanks
    0
    Thanked 6 Times in 4 Posts
    Hi everyone...i was curious from this posting therefore I had to check it out myself and we did!!! i got my friend to take a picture and scan it through obd II to see the difference, hence you see in the pictures that it is off. I would like to hear from everyone their inputs on this situation.

    Attachment 452Attachment 452Attachment 453Attachment 454
    Last edited by hyedegha; 06-29-2014 at 12:47 AM.

  9. #19
    Member
    Join Date
    Jun 2014
    Posts
    38
    Garage empty: add car
    Thanks
    0
    Thanked 6 Times in 4 Posts
    Quote Originally Posted by hyedegha View Post
    Hi everyone...i was curious from this posting therefore I had to check it out myself and we did!!! i got my friend to take a picture and scan it through obd II to see the difference, hence you see in the pictures that it is off. I would like to hear from everyone their inputs on this situation.

    Attachment 452Attachment 452Attachment 453Attachment 454
    Thank goodness for auto save/restore!!!!

  10. #20
    Senior Member Howie's Avatar
    Join Date
    Jun 2014
    Location
    Trenton, Ontario, Canada
    Posts
    752
    Thanks
    86
    Thanked 223 Times in 146 Posts
    GPS can vary quite wildly depending on a few things, namely a clear view of the sky.

    On some cars, the ECU takes the reading from the ABS module at each tire and then the average out of the 4. Some cars use a sensor at the transmission. Older jeeps have a gear that spins in the xfer case If I remember right.


        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S automatic: 7.9 L/100 km ... 35.7 mpg (Imp) ... 12.6 km/L ... 29.7 mpg (US) ...


Posting Permissions

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