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Old TN User
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Discussion Starter · #1 · (Edited)
When i first picked up my LE car in December, I noticed that when I went the same speed (according to the speedometer) as I used to drive with my previous 2000 Camry, everyone was passing me.

Well, I've since driven by three different portable radar speed control units and they all show, at various speeds, that my speedometer is 2mph too fast. (It shows 50 when the radar units say I'm actually going 48)

Has anyone else noticed this?

The car has the original all weather Michelin Energy tires inflated properly. I'm now also wondering if the speedometer is off, so too must be the odometer. If so, my car is adding up more miles than actually driven. I know... not that many more, but i like the meters to be accurate.
 

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2007 Camry XLE
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I have the same problem on my XLE, I had the same problem with my 03 Honda Accord. Honda checked out the Acord and said all was OK, Don't know if the odometer is affected for sure but I think it is since on trips the road side markers don't add up either. Hope you find an answer and let us know
 

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I recently took a road trip on my 4 cylinder XLE. Using my GPS unit I also noticed that the speedometer was reading 1-1/2 to 2 miles higher than the GPS showed. That's still pretty accurate in my experience.

Mike
 

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Mike Gerber said:
I recently took a road trip on my 4 cylinder XLE. Using my GPS unit I also noticed that the speedometer was reading 1-1/2 to 2 miles higher than the GPS showed. That's still pretty accurate in my experience.

Mike
In your case, the GPS was off depending on the ground truth and angle to satellite.
 

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Maven
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I've noticed that speedometers have read a little high on the last three Toyotas I've owned. My '07 is no exception and reads 70 when I am plugging along at a mere 69, which is closer than the last one. One of the first things I do with a new car is find an empty stretch of flat interstate, set the speed control and click away with a stop watch between mile markers and figure the speed.
 

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Old TN User
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Discussion Starter · #7 ·
Well, it looks like it's in tolerance. They've always been right on target in my previous Toyotas... at least according to those portable radar speed units on the side of the road. Guess I won't worry too much about it.

Thanks for the responses.
 

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Your speedometer is probably correct. I am radar and laser certified. One area covered in the radar class was how angles effect speed readout. I remember and have seen first hand that a radar at an angle shows a slower speed than the car is actually travelling at. The more angle, the slower the speed shown on the radar. The variation is generally as much as 5mph and sometimes more. The radar sign was on the side of the road. That means it was at an angle. More than likely the angle is what caused the slower reading. There is a formula that shows the exact mph correction for degrees of angle, but I am not going to look for the book. As a side note, your variation is far better than that of my crown vic. I have my speedometer checked every 6 months. I am 4mph off at 60mph every time.

Ever notice how the guy who passes you is a reckless driver, and the guy in front of you is a grandpa who needs to get out of the way.... LOL.
 

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gdanaher said:
I've noticed that speedometers have read a little high on the last three Toyotas I've owned. My '07 is no exception and reads 70 when I am plugging along at a mere 69, which is closer than the last one. One of the first things I do with a new car is find an empty stretch of flat interstate, set the speed control and click away with a stop watch between mile markers and figure the speed.
Don't forget the margin of error in your own reaction time and visual of when you actually 'hit' the starty and finish points.

As for the radar angular error margin, it is called the cosine error and in your class yu were probably taught Cosine Effect Geometry calculations to compensate.

 
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