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My feel for driving at 40mph in all of my vehicles has been right on for all of them. I just got this 2015 and noticed that when I felt like I was going 40mph the speedometer shows 44-45. I figured I had to get used to it. Well I went by a radar near a school going 35 with the speedo and the radar showed 32mph.
Does anyone else feel their speedo is off a few mph's?
Thanks in advance.
tm
 

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They are never exact. There is a tolerance where they have to be within a certain range of correct unfortunately. I certainly can't *feel* the difference between 35 and 32. If you are used to sedans though that could be part of it. I always find the lower a vehicle is the faster it feels at a given speed.
 

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My 2015 shows the same as yours. Occasionally I put the Garmin on the dashboard and it displays MPH so I know the correction factor. I made a small Excel program giving MPH at each gear and at 2000 RPM the speed is 68.5 MPH. The chart assumes the torque converter is locked up.

Frank 2015 Rav4 XLE with 7340 miles
 

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Different suspension feel, ride height, and the size of the vehicle all impact how fast it "feels" like you are going.
A vehicle where you are sitting very close to the ground, like an FRS, will "feel" much faster than a Rav or a Tundra at the same speed.
 

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Speedometer off vs. warranty

The speedometer on my 2014 Rav4 is about 5% off. If it shows 40, I am actually going 38 and if it shows 80, I am doing 76. Not that big a deal except when you think how it makes your 36000 mile warranty a 34,200 mile warranty. I asked my Toyota dealership if they could fix it and of course they said they have never heard of this problem and they could not recalibrate the speedometer. I wonder how much money Toyota saves in warranty costs if all of their vehicles have this issue. My 2013 Sequoia speedometer is spot on however.
 

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speedometer on 2014 limited

I have the same observation, overstated at low speed by about 5mph. We have a lot of speed cameras where I live so I use Speedbox (IOS App) or my GPS.
 

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The regulation in the USA requires a speedometer to be accurate to within plus or minus 5 mph at a speed of 50 mph. Toyota's display of higher than actual is in line with the norm. GM was sued, and lost, for certain models which displayed under actual speed.

Is the odometer actually coupled with the speedometer? It might be a separate calculation. Does anyone know for certain?

GPS is about the worst way to measure immediate MPH because it works best at highway cruising speeds and only when reception is strong, and it is best at averaging over miles, not within radar detector ranges. No court in the US will likely honor a GPS calculated speed for motor vehicles.

I have a couple GPS apps that measure speed and they are always dead wrong.
 

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The speedometer on my 2014 Rav4 is about 5% off. If it shows 40, I am actually going 38 and if it shows 80, I am doing 76. Not that big a deal except when you think how it makes your 36000 mile warranty a 34,200 mile warranty. I asked my Toyota dealership if they could fix it and of course they said they have never heard of this problem and they could not recalibrate the speedometer. I wonder how much money Toyota saves in warranty costs if all of their vehicles have this issue. My 2013 Sequoia speedometer is spot on however.
I also have a 2009 Nissan Versa, and Nissan was forced to do a recall to replace or repair the speedometer on some vehicles because of the concerns you mentioned for warranty and leasing reasons.

Frank 2015 Rav4 XLE with 7340 miles
 

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There are places that can calibrate the speedo. When I worked at a car dealership as a lot jockey we took cars to a place all the time. Which also confirms that a dealer doesn't do it. Not sure what is so specialized. I'd assume its access to a dyno.
 

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My speedo shows fast by 4% compared to my Garmin. All my other vehicles were right on.
 

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Set a speed alarm on your GPS and look at your speedo when the alarm goes off. You can get an idea of how accurate one may be over the other.
 

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Your Garmin is wrong. It simply cannot be correct.
I disagree.

GPS is a "reactive" reading, so if you are not holding a steady speed it will not be accurate, just as it can only tell you what heading you were on (don't even think of trying to "follow" a GPS to pilot a boat, you'll be zig-zagging all over the channel), but if you are holding your speedo at a constant 60 and the GPS reads 55, you can trust it.
Just realize that it's going to lag on speed variations.

As much as 10% over is common. It is pretty much the rule for Japanese motorcycles. Autos tend to be closer to 5%, but tire wear will influence that.

USDOT requires "within 10%" but many European countries have very stiff fines (on the manufacturer) if a speedo reads lower than actual, so manufacturers always err on the high side.


On the odometer... We have one VSS and all speed/distance information comes from that.
Honda got spanked a few years back in civil court and ended up having to give away a lot of extended warranties, so the odometers are typically within 5%.
Honestly, even with the 10% error, the Honda warranties were only expiring 3,000 miles early, and when buying a used car, are you going to think any worse of a vehicle with 110,000 than one with 100,000?

Similar for the speedo error.
Trust your speedo and relax knowing that if you're a little over coming down a hill, you aren't going to get a ticket.
10% or less really isn't much.
 

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Your Garmin is wrong. It simply cannot be correct.
Not sure why you are so adamant about that, but I disagree also. My readings were taken at a constant 100kph on the highway in a good satellite coverage area.
 

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Not sure why you are so adamant about that, but I disagree also. My readings were taken at a constant 100kph on the highway in a good satellite coverage area.
We agree.

In my earlier post I mentioned that reading GPS for speed works better at highway speeds (because the vehicle covers greater distance), and when reception is clear.
 

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An automotive type GPS receiver (GPSR) calculates your position on the face of the earth about every 1 second. It then determines how fast you must have been moving in order to travel that distance.

If you were traveling 900 MPH on a circular 1/4 mile, high school track, you would be in the same position every second when the GPS calculated your position, and it would show your speed as 0 MPH. The same type of error is introduced at a much smaller amount when you are driving on a curved road, since the distance you moved on the face of the earth would be less than the actual road length you traveled. The same is true when climbing a hill, the distance traveled on the road will be greater than the distance you moved on the face of the earth.

So to get the most accurate GPS speed calculations, you should be traveling in a straight line on level roads.

Another type of error is that the signals received from the satellites can delayed by atmospheric events or reflections from tall buildings. This type of interference can change from one second to the next, resulting in the calculation of your location being slightly different every second. In fact one reading could be several meters away from the previous reading which often results in hiking type GPSRs showing movement when you are stationary. Automotive GPSRs are designed to show the speed as 0 when the vehicle drops below walking speed for a few seconds. The automotive GPSR is also designed to show your location on the nearest road, despite the fact that the calculations may show you driving in a field between 2 roads. Note that this error between consecutive readings is different than the Estimated Position Error (EPE) which is based on the geometry of the satellites and is a fairly constant error over a short time period and small geographic area.

If you try and measure your speed when walking, then these positional errors of a few feet can be significant, but when traveling on the highway, the distance error of a few feet is negligible when calculating your speed.

So to summarize, in order to check your RAV's speedometer most accurately it should be done on a straight and level road at highway speeds for several seconds so that a single bad reading can be ignored. I always trust my GPSR readings over my vehicles speedometer. In fact whenever I purchase new tires, the first thing I do is check my speed with the GPSR.
 

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An automotive type GPS receiver (GPSR) calculates your position on the face of the earth about every 1 second. It then determines how fast you must have been moving in order to travel that distance.

If you were traveling 900 MPH on a circular 1/4 mile, high school track, you would be in the same position every second when the GPS calculated your position, and it would show your speed as 0 MPH. The same type of error is introduced at a much smaller amount when you are driving on a curved road, since the distance you moved on the face of the earth would be less than the actual road length you traveled. The same is true when climbing a hill, the distance traveled on the road will be greater than the distance you moved on the face of the earth.

So to get the most accurate GPS speed calculations, you should be traveling in a straight line on level roads.

Another type of error is that the signals received from the satellites can delayed by atmospheric events or reflections from tall buildings. This type of interference can change from one second to the next, resulting in the calculation of your location being slightly different every second. In fact one reading could be several meters away from the previous reading which often results in hiking type GPSRs showing movement when you are stationary. Automotive GPSRs are designed to show the speed as 0 when the vehicle drops below walking speed for a few seconds. The automotive GPSR is also designed to show your location on the nearest road, despite the fact that the calculations may show you driving in a field between 2 roads. Note that this error between consecutive readings is different than the Estimated Position Error (EPE) which is based on the geometry of the satellites and is a fairly constant error over a short time period and small geographic area.

If you try and measure your speed when walking, then these positional errors of a few feet can be significant, but when traveling on the highway, the distance error of a few feet is negligible when calculating your speed.

So to summarize, in order to check your RAV's speedometer most accurately it should be done on a straight and level road at highway speeds for several seconds so that a single bad reading can be ignored. I always trust my GPSR readings over my vehicles speedometer. In fact whenever I purchase new tires, the first thing I do is check my speed with the GPSR.

Amen to that! ?
 

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i have checked my speedo many times with gps, as well our other two vehicles, astro one mph off, camry almost dead on

my rav is 2.5 too fast up to about 50mph then seems to be 2.0 fast above that

the speedo and the odometer are two different things

after checking the odometer on one tenth of mile markers and on i 80, and one mile markers on pa tp and nj tp the odometer seen to be dead on

also the the piss poor fuel mileage, my average is 30.1 in hot weather, almost the same by doing the paper and pencil thing, with in in one tenth

but as the temps drop to the coldest in the winter the cars comp reads 2.5 miles per gallon higher than actual
 

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Rickl is quite correct. A differential GPS system would be needed to eliminate positional errors. It is amazing how much a position wanders when the GPS receiver is stationary. This wandering position is then transmitted to the GPS receiver you are using and corrections are made and then your position and speed would be correct. If the "P" codes are turned off the satellites accuracy goes down the tube for Most civilian GPS receivers.
 
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