Speedo Error?

[Doug9678]

Went out this morning with my buddy in his car and my indicated speed was 70 ( no gps) and my friend was doing 70 in his car.

So it seems like i have a pretty accurate speedometer.

I have read so many times that the speedos on these scoots are about 10% off.

Good to know that my scoot is fairly accurate , now i wont get a speeding ticket.

[axy]

Went out this morning with my buddy in his car and my indicated speed was 70 ( no gps) and my friend was doing 70 in his car.

So it seems like i have a pretty accurate speedometer.

As accurate as your friend's car, in fact.

[Doug9678]

I knew i would have naysayers , now you are saying car speedos are inaccurate?

Trust me 70 feels like 70 !

The gps in his car said 70 also......

[JustWantToRide]

My Xciting 500Ri is more accurate than any other bike I've had.  It's only 2.7% optimistic.  That was checked with a GPS with the bike reading 60, and then at 85 (same percentage).  I was hearing they were 15% off and such.  Not mine - but you'll notice the same naysayers chime in to argue points on bikes they don't even have...

[axy]

I knew i would have naysayers , now you are saying car speedos are inaccurate?

Yes, on average 6-15 %, however the error is not constant across the range, it increases as you go faster and it is highly dependent on type of vehicle, tires, brand and model.

There is a number of international standards covering this area and you can look them up on the Web if you are interested. Car speedometers are allowed to be off up to 14 % (meaning going actually 86 km/h when the speed shows 100 km/h). A piece of anecdotal evidence, I have a new car and at its top speed of 189 km/h it actually shows 195 km/h, meaning error of 3-4 % and it is pretty constant at lower speeds too). However, my People shows at least 10 km/h more from the very beginning, 15 km/h above 120-130 km/h, ditto for Agility, my old Beverly was slightly better, Piaggio NRG was just as bad as Kymcos etc.

Both car magazines and Web portals have frequent specials and tests of speedometers, so this is not exactly something new, neither is the error property of measuring instruments. We used to learn about it somewhere in elementary school.

Sometimes, naysayer is another word for somebody objective and better informed than average.

[Doug9678]

No , you are just arrogant and less prone to admit you are wrong than average.

Me to police officer after he pulls me over for speeding - " But officer, Axy on the internetz, says all speedos read faster than the actual speed i am going "

Officer just laughs and says , while writing out my ticket , "dont believe everything you read on the internet son."

[juice]

These days it is easy enough to verify with a GPS , and those I do trust .

[Doug9678]

Out of 231 cars tested by Car and Driver magazine  the average speedometer error  is 1.3 mph !

That certainly isnt 5% or 10% , in fact it is  less than 2% error!!


Read for yourself!    http://www.caranddriver.com/features/02q2/speedometer_scandal!-feature

Cars in the USA are allowed up to 4% error not 14% like he claims.  --------  


   In the U.S., manufacturers voluntarily follow the standard set by the Society of Automotive Engineers, J1226, which is pretty lax. To begin with, manufacturers are afforded the latitude to aim for within plus-or-minus two percent of absolute accuracy or to introduce bias to read high on a sliding scale of from minus-one to plus-three percent at low speeds to zero to plus-four percent above 55 mph.

 Who needs to go back to school ?

[axy]

Out of 231 cars tested by Car and Driver magazine  the average speedometer error  is 1.3 mph !

That certainly isnt 5% or 10% , in fact it is  less than 2% error!!


Read for yourself!    http://www.caranddriver.com/features/02q2/speedometer_scandal!-feature

Cars in the USA are allowed up to 4% error not 14% like he claims.  --------  


   In the U.S., manufacturers voluntarily follow the standard set by the Society of Automotive Engineers, J1226, which is pretty lax. To begin with, manufacturers are afforded the latitude to aim for within plus-or-minus two percent of absolute accuracy or to introduce bias to read high on a sliding scale of from minus-one to plus-three percent at low speeds to zero to plus-four percent above 55 mph.

 Who needs to go back to school ?

I am so glad for you and your 70 mph. I bet this Iridium spark plug and synthetic oil add at least 2 mph to that manly top speed.
Enjoy the rest of your life - it serves me right for trying to educate somebody who is determining accuracy of a scooter speedo by using car's speedo as absolute reference.

p.s. Unless it is not quite clear to you, Kymco scooter is not US manufactured product. I hope you know there are other countries in the world except USA, around 200+ of them.

[Doug9678]

Well my manhood wasn't threatened , obviously yours was.  LOL

[Spwoody]

Mine is about 5% optimistic. I have checked at several speeds with different GPS's. I would rather it be that way than the other way around.