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How accurate is your speedometer? I just noticed today that it is little higher than it should be. I was driving by one of those speed indicators on GW parkway, just south of D.C., my car read 60 mph but the sign was reading me at 58 mph. I quickly looked around to verify that I was the only one right then. There has been no upgrade on the car. The tires have only 1400 miles on it. Is that within standard error tolerance?
Around my area, cruisers are set up with digital speed indicators and radar. I have gone thru these many times at speeds of 30 to 60 mph and my speedo always reads 1 mph higher than what radar says I am doing.
According to my GPS my speedo is about 2 mph high at normal driving speeds. When I get up around 70 mph it is about 3-4 mph high.
This is better then my Prelude, that one is really high. At around 70 mph it is almost 5 mph high. Of course that is comparing to the GPS that might be low.
On my '02 S, the speedo is accurate, within 1 mph, all the way up to 80 mph according to GPS. I've not tested it faster than that.
On my 2000 Honda VFR800 motorcycle, the speedo reads 7% high at all speeds . . . this seems to be common for Honda motorcycles. Since the speedo's are digital, this error is intentional. I complained to the dealer and he checked with Honda to see if they would repair my MC speedo under warrantee. They refused, saying that 10% high was the tolerance level!!
I checked my speedometer several times using highway mileage markers and found it to be about 2% high (with fairly worn tires). So that would be 2 mph off at 100.
My wife's 2000 VW Beetle is nearly 10% off. That's bad.
I had a local cop radar me at 45mph and 70 mph, my spedo was off by 1 mph in both instances (which tripped me out since I have 18" tires now and I felt the error would be worse). Funny thing is, the cop told me that in his experience the spedo error does not increase with speed, and he had tested such. I always thought just like Chris stated, it's gonna' get way outa' line @ 150, but we will never know until someone actually tests it on several cars to get a baseline error.
Why do some people have to ask these questions???? I am a race director for the Nevada Silverstate Classic and the one S2000 owner posted his comments.........searching.
Found it.....damn I'm good ......notice he too hasd a Pantera which is why I could find his post :
Y2K01Y
Neutral
Member Since: Dec 2000
Status: Enthusiast
Location: Provo UT US
Posts: 8
Silver State Road Race results:
We came in 4th in the 105 mph class, at an average speed of 104.9453 mph. Winning average 104.9806 mph. Had we relied on Honda's "quality" speedometer, we would have averaged about 100 mph with the odmeter reading 94.5 miles at the finish, instead of exactly 90 as the GPS indicated.
Which BTW cheats me out of about 1800 miles of warrenty by my calculation.
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quote:
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Y2K1871
1971 Pantera Red 400 HP
TEAM PANTERA RACEING
If your not on the edge you are taking up space -
2001 S2000 Honda Yellow
Silver State Road Race Machine
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05-04-2001, 08:45 PM
......notice he too hasd a Pantera which is why I could find his post 
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