Speedometer Error?

xSTIx · 11-21-2005, 06:52 PM

Ok, after 19000 miles on my STI, I drive past one of those radar stations which reads your speed digitally, and it was 4mph lower than my stated speed.

A friend told me there were some more in certain areas, so I went by them all, and the result was an average of 4.5mph slower than my speedo.

Now, this might tell me I have a calibration for 18" wheels since my actual speed is slower than my radar speed (I, in fact, have 17"). The speed was confirmed by riding next to several friends of mine at speed.

Does this mean my Odometer might be reading in error? If so, then I may have accumulated an additional 800 or so miles minimum in error.

Anyone direct me to a TB on this issue, or do you know of this already?

Thanks
I guess my point is, they should fix this error under warranty.

klaymon · 11-21-2005, 07:36 PM

This is not a warranty issue. There are threads here already if you search speedo error or speedometer error. Basically, it's about 5% off to the fast side. 60 MPH on the speedo is 57 on radar, 80 is 76, etc. There is no set amount it's off (5 MPH across the board for example). People have also confirmed that the ECU and odometer are dead on.

Speedometer Fast?
Speedometer error

CGMDan · 11-21-2005, 09:43 PM

HE does bring up a good point with the amount of error. You will accumilate more milage than what the car actually has. Who cares you say? For those of us still with a warrenty or other milage related issues we're getting shorted.
I hadn't thought of it like that.

klaymon · 11-22-2005, 03:13 AM

Someone here has already done some data logging and the ECU and odometer are correct (I can't remember who, search a few threads on this). The car does really know how fast and far it's going, it just does not display the speed 100% accurately.

Edit: The second thread I listed has entries where people had various hardware hooked up to the car to verify speed/distance (GPS, code scanners, etc.), even checking with interstate mile markers. Everything is cool, the speedo reads just a little high.

11-21-2005, 06:52 PM	#1
xSTIx STI Driver Car: 05 Blue STI Fav Mod: -10 degree C Ambient Air.. :) Still under warranty! Location: Illinois Posts: 228 Join Date: Aug 2004 Trader Rating: (0)	Speedometer Error? Ok, after 19000 miles on my STI, I drive past one of those radar stations which reads your speed digitally, and it was 4mph lower than my stated speed. A friend told me there were some more in certain areas, so I went by them all, and the result was an average of 4.5mph slower than my speedo. Now, this might tell me I have a calibration for 18" wheels since my actual speed is slower than my radar speed (I, in fact, have 17"). The speed was confirmed by riding next to several friends of mine at speed. Does this mean my Odometer might be reading in error? If so, then I may have accumulated an additional 800 or so miles minimum in error. Anyone direct me to a TB on this issue, or do you know of this already? Thanks I guess my point is, they should fix this error under warranty. This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by xSTIx : 11-22-2005 at 08:13 AM.

11-21-2005, 07:36 PM	#2
klaymon S204 Racer Posts: 3,083 Join Date: Jul 2004 Trader Rating: (1)	This is not a warranty issue. There are threads here already if you search speedo error or speedometer error. Basically, it's about 5% off to the fast side. 60 MPH on the speedo is 57 on radar, 80 is 76, etc. There is no set amount it's off (5 MPH across the board for example). People have also confirmed that the ECU and odometer are dead on. Speedometer Fast? Speedometer error Last edited by klaymon : 11-21-2005 at 07:41 PM.

11-22-2005, 03:13 AM	#4
klaymon S204 Racer Posts: 3,083 Join Date: Jul 2004 Trader Rating: (1)	Someone here has already done some data logging and the ECU and odometer are correct (I can't remember who, search a few threads on this). The car does really know how fast and far it's going, it just does not display the speed 100% accurately. Edit: The second thread I listed has entries where people had various hardware hooked up to the car to verify speed/distance (GPS, code scanners, etc.), even checking with interstate mile markers. Everything is cool, the speedo reads just a little high. This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by klaymon : 11-22-2005 at 03:25 AM.

11-21-2005, 09:43 PM	#3
CGMDan Spec C Club Car: '05 CGM STi Fav Mod: What's RCE made lately? Location: Beaverton, Or Posts: 1,467 Join Date: Nov 2004 Trader Rating: (0)	HE does bring up a good point with the amount of error. You will accumilate more milage than what the car actually has. Who cares you say? For those of us still with a warrenty or other milage related issues we're getting shorted. I hadn't thought of it like that.