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06-07-2010, 08:37 AM | #1 |
Drives: 09' Yaris Liftback and 06' FZ1 Join Date: Jan 2009
Location: Red Wing, MN
Posts: 24
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Speedometer Accuracy?
I have an 09' Yaris LB with an automatic transmission. I drive a lot and when going 55 mph (according to the speedometer) I get passed a lot. When I drive my Durango 55 mph, I pass a lot.
So I tracked it with my GPS and when the speedometer says 55 mph, the GPS says about 52/53. I wonder which is correct? My guess is that the GPS is correct or else I've suddenly begun driving like I was 90 years old! |
06-07-2010, 09:21 AM | #2 |
Drives: Big Yellow Join Date: May 2009
Location: Somewhere in the vacinity of Betelgeuse
Posts: 179
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Were you the 1st person to own the car? It could be that the previous owner had put on larger diameter tires, changed the speedo gear and then switched back to the smaller tires for the sale without the changing the speedo gear back.
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06-07-2010, 10:38 AM | #3 |
Drives: 09' Yaris Liftback and 06' FZ1 Join Date: Jan 2009
Location: Red Wing, MN
Posts: 24
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I'm the original owner and the car is stock.
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06-07-2010, 12:18 PM | #4 |
Drives: 2008 Flint Mica Yaris Sedan Join Date: Jan 2010
Location: Augusta, GA
Posts: 29
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I have a Yaris with stock wheels as well. I believe the problem may lie in the fact that the bare-bones stock Yaris comes with 14" wheels and every other Yaris comes with 15" wheels (or bigger). The speedometer may be calibrated for the 14" wheels.... or it could just be that Toyota set it to show higher than it is actually going to keep you from getting tickets.
I realized this anomaly a month or two after I bought my Yaris and have since corrected my speed by going approximately 5% faster than what the speed limit is (68 in a 65, 37 in a 35, etc.). |
06-07-2010, 01:00 PM | #5 |
vroom vroom
Drives: lil red 5-door Join Date: Sep 2006
Location: Bangkok, Thailand
Posts: 7,744
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It seems to be a problem with most yaris (and I heard the Fit did that too). One might think it's a safety feature to get people driving slower, who knows...
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The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish. - Robert Jackson Bye bye 1NZ... |
06-07-2010, 02:03 PM | #6 |
Drives: 09' Yaris Liftback and 06' FZ1 Join Date: Jan 2009
Location: Red Wing, MN
Posts: 24
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I guess I was a little surprised by it. The difference is even more on my motorcycle and I suppose I'll get out and measure the Durango.
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06-07-2010, 03:10 PM | #7 |
Half a Bubble Off Plumb
Drives: 2009 Yaris Sedan Join Date: Mar 2009
Location: Bristol, Tennessee, USA
Posts: 1,593
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It's already been posted on here that there are different speedometer drive gears for the 14" and 15" wheels. Your tires are either smaller in diameter than the ones it was calibrated for, or underinflated.
May be an issue with reading the speedometer, too. Due to the speedometer being in the center, there's parallax viewing it from normal driving position. It's meant to be viewed from straight on, meaning your head in the center between the seats. From my normal position, if I put the left edge of the speedometer on the right edge of the 55 mark, it's centered over it if I do move my head over to the center. |
06-07-2010, 03:13 PM | #8 |
Drives: Big Yellow Join Date: May 2009
Location: Somewhere in the vacinity of Betelgeuse
Posts: 179
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That's weird, mine is a 2009 LB MT with stock 15" wheels and it's always matched my GPS.
I that were mine, I'd definitely verify it with another car and if it was still off, I'd be taking it to the dealership. Who knows, the car may even have been built with the wrong speedo gear. EDIT: what YH said, you should definitely check your tire pressure. |
06-07-2010, 04:46 PM | #9 |
Drives: 2010 Yaris "5-door" Join Date: Mar 2009
Location: Upper Waiakea Forest Reserve
Posts: 170
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This is the way speedometers are designed. They typically read 3% or more faster than the true speed.
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06-07-2010, 06:11 PM | #10 | |
Quote:
On a side note, there was some speculation a few years ago that car makers were manufacturing the speedometers and the related hardware so that it always read faster than what the car was going. This runs the warranty out quicker and before the car hits high enough actual miles to end the warranty. For example, if your speedo reads 5% higher than actual speed then your Odometer is also reading the miles 5% faster. On a car with a 36,000 mile warranty, at 5%, the car has only actually traveled 34,200 miles when the Odometer reads 36,000 (OP's post indicates around a 4.5% variance so he has approximately a 34,400 mile warranty). Obviously, the higher the mileage limit on a warranty, and the bigger the variation form true speed, the more beneficial it is to the manufacturer to have the speedo read higher than actual speeds and register miles faster than it should. |
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06-07-2010, 06:47 PM | #11 |
Drives: 2010 Yaris "5-door" Join Date: Mar 2009
Location: Upper Waiakea Forest Reserve
Posts: 170
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That isn't necessarily true. The speedometer needle could easily have an offset that makes it different from both the odometer and reality. (It's possible the offset is smaller and/or more linear than in the old days, though.)
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06-07-2010, 04:53 PM | #12 |
Drives: 2009 3DR Blizzard Pearl CE Join Date: Jul 2009
Location: Halifax, Nova Scotia
Posts: 77
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The problem is that other drivers assume you and your Yaris are slow, so they want to pass. I get passed more often in the Yaris than our other cars.
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06-07-2010, 04:59 PM | #13 |
DWEED
Drives: 3DR 2008 Metorite Metalic Join Date: Oct 2008
Location: Arizona
Posts: 1,161
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Mine is very accurate. Within .5%. Assuming that the speed odometer and the odometer are in sync, the best way to to test them is using the highway mile markers on a road trip. Press the milage reset button as you pass a marker and drive 10 miles. Then compare the difference. Do this 3 times to get an average. You can also drive exactly 60 mph and time how long it takes to drive 10 miles. Do the math and know exactly how accurate your speed odometer is.
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Making a decision without following it with an action is still a fantasy. |
06-07-2010, 06:10 PM | #14 |
Drives: 2008 Yaris Hatchback Join Date: Jan 2010
Location: Alabama
Posts: 64
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mine is 1.5 mph faster than the GPS
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06-07-2010, 06:16 PM | #15 |
"LibertyRides!"
Drives: 2010 Yaris 3Dr LB | 2020 Stang Join Date: Mar 2010
Location: State College, PA, USA
Posts: 576
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Mine is a 2010 with 15" steel wheels...
GPS is dead on! I'll have to try the mile marker to mile marker for ten miles @ 60MPH to see how it matches up! Thanks
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~ Mark ~ 2010 Yaris 3-Dr Liftback, 5-Speed Manual, P185/60R 15, Bayou Blue Pearl I Love my YARIS - (Click below to see Gaslog): Most miles Tank: 538 tank/10.148 gal = 53.015 MPG / Most MPG: 54.95 MPG (ethanol) 425 tank/7.73 gal "The evils of government are directly proportional to the tolerance of the people." -- Frank Kent |
06-07-2010, 06:33 PM | #16 |
Drives: 2010 Yaris 3 door Join Date: Feb 2010
Location: Parma, OH
Posts: 53
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I find my speedometer to be accurate within 1 mph. As a side note, my old Entourage was off by 3 mph at 65 and my wife's Sonata is off by 2 at 65. I had the misfortune of renting a Dodge Caliber and it was spot on accurate for what it's worth!
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06-09-2010, 11:26 AM | #17 |
Drives: 2007 Toyota Yairs Join Date: Jul 2007
Location: .
Posts: 36
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Yep - the Caliber reports its 0mph very accurately! I had the misfortune of passenger-ing in my brother's rented one. 0-65 in about a month or so; the National Car of Florida!
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06-09-2010, 09:47 PM | #18 |
Drives: 2007 Silver 3dr hatch Join Date: Mar 2010
Location: Lewisville, TX
Posts: 52
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Both Wheel and tire size can definately affect the speedometer.
I've got 18" Wheels with 215 35 18 tires on them...thought at first that the car seemed like it was going faster cause it was lowered and the ride was more severe...flipped on the GPS and was going 6 MPH faster than I thought I was(speedometer is normally over the speed limit anyways) I've adjusted that since, lol
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See Pictures of My Yaris at WWW.DusoldEnterprises.com |
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