Speedometer Inaccuracy
#1
donuts are day old bagels
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Speedometer Inaccuracy
I took a trip to Vegas last weekend. Had good times, lost a pile of money, etc. On hwy 15, they have implemented these neat little speed detectors on downhills, shows you how fast you are going and tells you to slow down. A great safety measure, infinitely better than camping police cars that make idiots slam their brakes.
So, I'm cruising along and I pass the first such signs, it is flashing that I am travelling at 72mph. Hmm... my speedo is showing 80.... but whatever. Between LV and LA there are at least 3 such signs, so I made sure to check the speedo at each sign. I was slightly perturbed to see that the speedo was off by 5 ~ 7 mph ( I drove back a few times to make sure it was right, and well, it's fun to see how big the numbers go.)
I know that it isn't uncommon for speedo's to be off, but I've never had a car that was off by this much. Hopefully its just my car. I'd take it to the dealer to have em check it out but I can't come up with a good excuse to give to the techie.
So, I'm cruising along and I pass the first such signs, it is flashing that I am travelling at 72mph. Hmm... my speedo is showing 80.... but whatever. Between LV and LA there are at least 3 such signs, so I made sure to check the speedo at each sign. I was slightly perturbed to see that the speedo was off by 5 ~ 7 mph ( I drove back a few times to make sure it was right, and well, it's fun to see how big the numbers go.)
I know that it isn't uncommon for speedo's to be off, but I've never had a car that was off by this much. Hopefully its just my car. I'd take it to the dealer to have em check it out but I can't come up with a good excuse to give to the techie.
#4
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Originally Posted by RX8Bliss
A great safety measure, infinitely better than camping police cars that make idiots slam their brakes.
I know that it isn't uncommon for speedo's to be off, but I've never had a car that was off by this much. Hopefully its just my car. I'd take it to the dealer to have em check it out but I can't come up with a good excuse to give to the techie.
I know that it isn't uncommon for speedo's to be off, but I've never had a car that was off by this much. Hopefully its just my car. I'd take it to the dealer to have em check it out but I can't come up with a good excuse to give to the techie.
I'd actually be more suspicious of the machine than your car. I've seen many of these around where I live, and in every car I drive it always seems a bit off....The odds seem more against the silly machine than your car...but this is just my thought...
#6
I was flashed by an traffic surveillance cam in September.
My speedo showed 108/109 km/h when the flash came.
When the bill came I was clocked at 102 km/h.
I know they use some km/h margin,so I don't think it was that bad.
The bill was 2200 NOK(350$) for 102km/h in 80-limit
My speedo showed 108/109 km/h when the flash came.
When the bill came I was clocked at 102 km/h.
I know they use some km/h margin,so I don't think it was that bad.
The bill was 2200 NOK(350$) for 102km/h in 80-limit
#7
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I recall this being discussed before and the speedometers were reading 2mph faster than the 8 was travelling.
I took a portable GPS with a speed reading out with the 8 and found mine to be consistantly 1.8 mph slower than the speedometer output. Tested at various speeds
5-7mph off is excessive better check it out.
I took a portable GPS with a speed reading out with the 8 and found mine to be consistantly 1.8 mph slower than the speedometer output. Tested at various speeds
5-7mph off is excessive better check it out.
Last edited by RenoIV; 02-21-2005 at 03:56 PM. Reason: spelling
#8
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I checked my speedometer using GPS and it was remarkably accurate. Whether that is more accurate than the radar-signs is the question. If you want to read a thread that discusses this as well as odometer accuracy do a search for GPS. I think that second thread that comes up is the one you want.
#9
Originally Posted by RenoIV
I took a portable GPS with a speed reading out tht the 8 and found mine to be consistantly 1.8 mph slower than the speedometer output. Tested at various speeds
5-7mph off is excessive better check it out
5-7mph off is excessive better check it out
German magazine Auto Motor und Sport tested the RX-8 about a year ago.
The inaccuracy was 3 km/h at every speed tested.
I.e. the speedo showed 3 km/h more than real speed.
They tested it up to 160km/h.
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