TCH Odometer accuracy

Discussion in 'Toyota Camry Hybrid' started by DaveJ, Jun 7, 2013.

  1. DaveJ

    DaveJ Well-Known Member

    I did two more odometer tests. Last weekend on a trip over 100 miles, I checked ODO vs: GPS.100 miles odo equaled 103.2 miles GPS.(Did this both ways)
    After that a friend questioned accuracy of GPS and suggested checking with mile markers.
    Today, I did a 30 mile check.
    At 10 miles per marker = 9.7 ODO
    At 20 miles marker = 19.4 ODO
    At 30 miles marker = 29.0 ODO
    Gps was very, very close to mile markers, within a few hundred feet in 30 miles.
    I stopped at 1st mile marker and set GPS, Trip ODO both to zero.
    I stopped at 30 mile marker to get end reading.
    So, my ODO is off(low) by 3.2% GPS, 3.33% mile marker.
    Would a couple others try the same test and report results, please.
    This would increase mpg from calculated results using odo and gal.
    by a little more than 3%
    2012 Black Camry Hybrid LE
  2. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Hi Dave,

    Sorry I can't help with useful data, but I'd like to consider other possibilities.

    What is the tire size and brand/model, and is it the stock tire that Toyota delivered?

  3. DaveJ

    DaveJ Well-Known Member

    Stock tire, Michelin X green Energy saver A/S P205X65R16

    I'm not unhappy with results, and it is very close to what I got on a 2008 Corolla.
    I'm just curious if all are like mine.
  4. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Hi Dave,

    Sorry for this dead end... just due diligence. That's certainly the stock
    size. I, too, would wonder about that much error on the odo. On the
    bright side, the error's on your side as far as resale goes. Just check the
    speedo to see that it doesn't similarly underreport. :)

    Of course, I haven't checked my own vehicles' odos. Ignorance is bliss
    in my case. :) I usually only check the speedo to make sure I can trust


    addendum: Just had a thought. Do hyperinflated tires have a higher
    circumference than those inflated to placard specs?
    Last edited: Jun 8, 2013
  5. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    With the car underestimating distance travelled I can see a couple of things happening:

    1. Your warranty is extended ;)
    2. Your mpg cac's are going to be a little off (on the rosy side), unless you factor in the error.
  6. ALS

    ALS Super Moderator Staff Member

    Just to update you on the manufacture/DOT fudge factor when it comes to odometers. There is a built in offset so that the speedometer always reads high. This is so that the car will always run slower than odometer states even with brand new unworn tires. My Prius reads 58-59 mph on the GPS vs 60 mph on the speedometer. This is a little Government mandated speed protection from over zealous police speed traps. The speedometer should only be off at most by one to two mph. At 30 mph my GPS is reading 29 mph and at 55 the GPS reads 53-54 mph. I've checked using mile markers and two different GPS systems, a Garmin and a DeLorme mapping software GPS unit and as in your case the GPS is pretty close to dead on and the speedometer is the one off.

    Dave if your odometer is reading low then you got one of the good ones like Mendel Leisk pointed out. Honda got nailed a few years ago for odometers that were reading high and had to payout some money and extend warranties to cover the high reading odometers. You just got your self another free 1500 miles added on to your 36K mile warranty. :)
    Last edited: Jun 8, 2013
  7. RedylC94

    RedylC94 Well-Known Member

    Back in the days of mechanically cable-driven eddy-current speedometers, I checked odometers and speedometers on a lot of new cars. Almost all showed above actual distance and speed, by around 1-4%, although one Plymouth was high by something like 11%, and my Subaru was 5% high.

    Does the new speedometer regulation require it to overestimate by a specific amount, or merely require that it must not show less than actual (which would effectively require the manufacturer to make it show at least a little high to allow for normal manufacturing tolerances on tires, etc.)?

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