Topic 'How do you determine if your speedometer is accurate?' in forum 'Automotive'

Topic 'How do you determine if your speedometer is accurate?' in forum 'Automotive' - dslreports.com http://www.dslreports.com/forum/How-do-you-determine-if-your-speedometer-is-accurate-23287917 en Fri, 10 Feb 2012 12:58:37 EDT Fri, 10 Feb 2012 12:58:37 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23330175 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23330175 Thu, 12 Nov 2009 10:03:38 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23325391
Thanks again for the tip about using a GPS. ]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23325391 Wed, 11 Nov 2009 11:56:22 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23324268 said by Karride:

All joking aside, I have on a couple of occasions with my project car pulled up to an officer clocking people on my street, and asked if he would clock me as I go by so I could determine my speedo's accuracy. Both times the cop was quite willing to help with this.
In the distant past, I asked for the same favor and my request was denied.
--
Humanity - The greatest natural disaster of all time.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23324268 Wed, 11 Nov 2009 08:08:37 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23323334 said by Karride:

said by jaa:

Drive a steady 85 down the highway. I'm sure a trooper will be glad to tell you how fast you were actually going.

All joking aside, I have on a couple of occasions with my project car pulled up to an officer clocking people on my street, and asked if he would clock me as I go by so I could determine my speedo's accuracy. Both times the cop was quite willing to help with this.
And then wrote me a ticket for being 10 mph over. :)]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23323334 Tue, 10 Nov 2009 22:46:40 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23313647 said by jaa:

Drive a steady 85 down the highway. I'm sure a trooper will be glad to tell you how fast you were actually going.
All joking aside, I have on a couple of occasions with my project car pulled up to an officer clocking people on my street, and asked if he would clock me as I go by so I could determine my speedo's accuracy. Both times the cop was quite willing to help with this.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23313647 Mon, 09 Nov 2009 09:45:20 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23308047 --
NOTHING justifies terrorism. We don't negotiate with terrorists. Those that support terrorists are terrorists.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23308047 Sat, 07 Nov 2009 21:08:51 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23304345 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23304345 Fri, 06 Nov 2009 21:08:02 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23303739 said by Waterbug:

Your speedometer and odometer run off of the same gears.
This may be true but the speedometer can still be off. At highway speed, our analog speedometer is always about 10km/h over. (verified with GPS) I always wondered if the digital odometer was off as well but on a trip from Detroit to Toronto it was dead on. The mile markers start at zero when you cross the border and highway 401 starts so it was easy to verify. It's a Volvo so it may be related to the post about Germans cars being possibly over by design.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23303739 Fri, 06 Nov 2009 18:43:52 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23299807 said by Vamp:

I kind of hate the fact it can be off, that means when your car is at 100k it could really be +/- a few percent.

Honda had a problem with this a few years back.

»www.autoblog.com/2007/02/19/odo-···on-cars/
--
In need of a Vegas vacation.
]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23299807 Fri, 06 Nov 2009 00:24:14 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23299792
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20/20 FIOS || MSN Msgr: scott001^gmail_com]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23299792 Fri, 06 Nov 2009 00:20:08 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23296152 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23296152 Thu, 05 Nov 2009 12:10:58 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295941 said by Doctor Olds:

said by lotusracer:

said by Doctor Olds:

Don't know where they are in relation to you but:

Speedometer & Clock Co

That is bad news. :[ I guess their niche market is drying up.
It is bad news. I sent them the speedometer from my Esprit several years ago when the odometer quit. The repair cost me $50. Had the thing back in around 7 days.
--
Humanity - The greatest natural disaster of all time.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295941 Thu, 05 Nov 2009 11:29:58 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295915 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295915 Thu, 05 Nov 2009 11:26:05 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295056 said by lotusracer:

said by Doctor Olds:

Don't know where they are in relation to you but:

Speedometer & Clock Co

I have used them in the past, but it is my belief that they are no longer there, or even in business at all. Think I tried calling them some time ago and the number was no longer in service.

Just tried calling that number and got a fax tone.
That is bad news. :[ I guess their niche market is drying up.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23295056 Thu, 05 Nov 2009 08:40:40 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294950 said by Doctor Olds:

Don't know where they are in relation to you but:

Speedometer & Clock Co
2337 S. Michigan Ave
Chicago, IL 60616-2104
(312) 842-6377
I have used them in the past, but it is my belief that they are no longer there, or even in business at all. Think I tried calling them some time ago and the number was no longer in service.

Just tried calling that number and got a fax tone.
--
Humanity - The greatest natural disaster of all time.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294950 Thu, 05 Nov 2009 08:05:44 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294629 said by No_Strings:

A most excellent suggestion.
I'd guess he completely glazed over this post of yours
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294629 Thu, 05 Nov 2009 03:55:41 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294545 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294545 Thu, 05 Nov 2009 02:19:08 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294505 --
Illinois: where the governors make the license plates!]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294505 Thu, 05 Nov 2009 01:47:44 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294195
The indicator needle has to come off to get the face off. Putting back together, discovered there is no 'flat spot' or other way to tell where the needle is supposed to go on the shaft.

Finally got the GPS out and had wife scrunch me close to the door and she sat close and steer and watch the GPS and when the GPS said "35 mph", I pinged the needle on the shaft. ]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23294195 Wed, 04 Nov 2009 23:53:37 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23291841 said by PrntRhd:

Most modern digital speedometers are adjusted for the correct display via jumpers on a circuit board, not by changing gears at the transmission.
Most modern cars are calibrated from inside the computer by using a calibration factor or a pinion factor.

This is not to say that the speedometer needle itself is not accurate. I had my instrument cluster replaced by GM under warranty (bad stepper motors). The one I got back was a reman, and the needle was physically off by 3mph. After complaining for two weeks, GM finally gave me a new one, and it was off by 2 mph. Finally, I just sent it off to be recalibrated and have a transmission temp gauge added.
--
"F is for Fire that burns down the whole town...
U is for Uranium...... Bombs...
N is for NO SURVIVORS!!!!!" Sheldon Plankton]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23291841 Wed, 04 Nov 2009 16:45:29 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23291220
However, the computer has the correct speed so if either you connect a laptop to view realtime data or e.g set cruise control @ 60mph on the speedometer and rest the average speed, it will show something like 57 mph.
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PRescott7-2097]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23291220 Wed, 04 Nov 2009 15:07:17 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23289375 Most modern digital speedometers are adjusted for the correct display via jumpers on a circuit board, not by changing gears at the transmission.
I cannot research further for your car because you did not post the yr/make/model.]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23289375 Wed, 04 Nov 2009 10:08:50 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23289248
I guess if I can drive to the east coast and back, I can make it down to Orland Park (or S. Michigan Ave.) sometime.

BTW, I did see the listing for the Speedometer & Clock Co last night, but somehow among the bicycle/motorcycle speedometer listings and Speedo listings that were returned, my mind said, "Nah! Can't be what I'm looking for."

P.S. I've intentionally taken multiple runs at those automated radar set-ups that show you your speed. A lot of them seemed to confirm that I'm going almost 10% slower than my speedometer is telling me, but many also show a much smaller discrepancy.

Thanks once again, folks!]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23289248 Wed, 04 Nov 2009 09:44:16 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288983 --
Brian

"It drops into your stomach like a Abrams's tank.... driven by Rosanne Barr..." A. Bourdain]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288983 Wed, 04 Nov 2009 08:48:39 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288927 said by Doctor Olds:

Huh? are you saying to go out and drive for an hour as a test for accuracy?
First line of the second paragraph of the OP: "I've been doing a lot of highway driving lately" If you're already on the road, it checks accuracy and helps kill the time. Beats counting telephone poles to pass time. :)]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288927 Wed, 04 Nov 2009 08:31:16 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288899 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288899 Wed, 04 Nov 2009 08:23:30 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288783 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288783 Wed, 04 Nov 2009 07:39:34 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288700 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288700 Wed, 04 Nov 2009 06:56:57 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288698 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288698 Wed, 04 Nov 2009 06:55:19 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288277 said by PrntRhd:

Google "speedometer repair Chicago:
»maps.google.com/maps/place?oe=ut···24517285
Yes, that shows as;

AJR Radio & Speedometer Inc
15549 S 71st Ct,
Orland Park, IL
(708) 429-4114
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288277 Wed, 04 Nov 2009 01:10:19 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288226 said by vircotto:

There is such a thing as a speedometer shop? (*slaps forehead* :o )

Okay, I just Googled for one in the Chicago, IL area and came up blank. Is there a better term (or more general term) that I might use in a search?
Don't know where they are in relation to you but:

Speedometer & Clock Co
2337 S. Michigan Ave
Chicago, IL 60616-2104
(312) 842-6377
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288226 Wed, 04 Nov 2009 00:51:17 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288154 said by vircotto:

There is such a thing as a speedometer shop? (*slaps forehead* :o )

Okay, I just Googled for one in the Chicago, IL area and came up blank. Is there a better term (or more general term) that I might use in a search?

Or if anyone knows of one in the (far) NW side of Chicago or suburbs, please chime in.

Thanks all!

Google "speedometer repair Chicago:
»maps.google.com/maps/place?oe=ut···24517285]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288154 Wed, 04 Nov 2009 00:30:56 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288140
Okay, I just Googled for one in the Chicago, IL area and came up blank. Is there a better term (or more general term) that I might use in a search?

Or if anyone knows of one in the (far) NW side of Chicago or suburbs, please chime in.

Thanks all!]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288140 Wed, 04 Nov 2009 00:27:46 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288044 --
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?]]> http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23288044 Tue, 03 Nov 2009 23:59:21 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23287935 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23287935 Tue, 03 Nov 2009 23:29:02 EDT Re: How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23287927 http://www.dslreports.com/forum/Re-How-do-you-determine-if-your-speedometer-is-accurate-23287927 Tue, 03 Nov 2009 23:27:55 EDT How do you determine if your speedometer is accurate? http://www.dslreports.com/forum/How-do-you-determine-if-your-speedometer-is-accurate-23287917
I've been doing a lot of highway driving lately and have noticed cars riding my bumper (even when I'm in the right lane and over the speed limit a bit). At first I just thought it was aggressive drivers, but then I considered that maybe I was going slower than my speedometer indicated. On several occasions when traffic was virtually non-existent, I set my speed control at 60 mph and timed myself over 10 miles (determined by the mile markers on the side of the road). I did the math and kept coming up in the 54-55 mph range. (With OEM tires/wheels, btw). Could my speedometer really be off that much? Is there an easy (and inexpensive) way to know for sure?]]> http://www.dslreports.com/forum/How-do-you-determine-if-your-speedometer-is-accurate-23287917 Tue, 03 Nov 2009 23:25:15 EDT