speedometer is off

Teknicz · March 2nd, 2010, 01:56 PM

when i drive my speedometer isnt accurate, it moves as normal but its about 15-20 miles off. Any reason why i usually just drive around with a gps that montiors the speed, but so far i hav gotten light weight pullies, bigger throttlebody intake and exhaust? Any opinions?

wraitherx · March 2nd, 2010, 02:15 PM

so you dont have any gears? some times those GPS things can be off by a little. What you can do is to enter into that test mode on the odometer and then keep pressing the button until you get to the digital speedo and it will tell you how fast you are going to compare.

Teknicz · March 3rd, 2010, 03:07 PM

test mode?? yea no gears atleast i dont kno if the owners before installed any. But yea the gps is off by a little,but yea i learned it on the freeway comin home from miami where i bought it. my car was goin 100 while my dad was crusing at 70 lol.. and i was wayy to slow when i was at 70

wraitherx · March 3rd, 2010, 05:45 PM

check this out for the test mode Mustangworld HEC Instrument Cluster Diagnostics

Justdoit04 · March 3rd, 2010, 05:49 PM

haha I'd contact the previous owner if you can ... thats significantly off ... need to get the speedometer recalibrated ... maybe the previously owner had it tuned for the set up they had on it

Teknicz · March 3rd, 2010, 05:51 PM

You freaking rock guy!

Doc8224 · March 3rd, 2010, 07:01 PM

what tire sizes do you have? and I agree the previous owner could have done the speedo recalibration to different gears then pulled the gears before he sold the car

F8L GT · March 3rd, 2010, 07:03 PM

Originally Posted by Doc8224

what tire sizes do you have? and I agree the previous owner could have done the speedo recalibration to different gears then pulled the gears before he sold the car

this was my case. previous owner put 3.73s in my car, never retuned for them. And now my odometer has way more miles than the car really has

Phoenixx · March 3rd, 2010, 07:07 PM

Originally Posted by F8L GT

this was my case. previous owner put 3.73s in my car, never retuned for them. And now my odometer has way more miles than the car really has

Yup that can make a substantial difference, if it's been lifted or lowered it can make a difference. If you're positive it's off by 15-20mph, you should have it recalibrated. It's not a big deal to have done.

wraitherx · March 3rd, 2010, 08:34 PM

pretty much what they are all saying is sound advice. Only thing that I was saying is not to go by what the GPS is saying since they are not meant to determine speed

but since you did say that you compared speeds with your dad then yes take it in to get it recalobrated.

Doc8224 · March 3rd, 2010, 09:22 PM

Originally Posted by Phoenixx

Yup that can make a substantial difference, if it's been lifted or lowered it can make a difference. If you're positive it's off by 15-20mph, you should have it recalibrated. It's not a big deal to have done.

The height of the vehicle won't make a difference just if the overall tire diameter has changed will it matter, or if the gears are different, or if the transmission speedo gear has been changed

Teknicz · March 3rd, 2010, 09:49 PM

Thanks for the input guys, but yea im pretty sure. I kno gps is off a mile or so. You can just tell the speedometer isnt right its too slow than how fast its goin.. maybe he did that with the gears, because i asked the guy i brought em from he said it stock when i first picked it up. It has the 03 cobra rims which is 275 width stock really.. but yea i appreciate the advice guys

Phoenixx · March 3rd, 2010, 09:59 PM

Originally Posted by Doc8224

The height of the vehicle won't make a difference just if the overall tire diameter has changed will it matter, or if the gears are different, or if the transmission speedo gear has been changed

Yes true, I suppose I was over simplifying. I was thinking my truck got lifted for bigger tires, and they forgot to make adjustments accordingly. I tend to assume that if people are lifting or dropping their cars they're changing tire diameter too :-)

March 2nd, 2010, 01:56 PM	#1
Teknicz Regular 99 mustang cobra Join Date: Nov 2009 Location: Orlando Posts: 206 iTrader: 0 reviews	speedometer is off when i drive my speedometer isnt accurate, it moves as normal but its about 15-20 miles off. Any reason why i usually just drive around with a gps that montiors the speed, but so far i hav gotten light weight pullies, bigger throttlebody intake and exhaust? Any opinions? __________________ NO CATS NO GLORY SLP LOUDMOUTH FTW MM Cobra Club #57

March 2nd, 2010, 02:15 PM	#2
wraitherx Moderator '99 SVT Cobra Join Date: Nov 2006 Location: Virginia Beach, VA Posts: 9,568 iTrader: 11 reviews	so you dont have any gears? some times those GPS things can be off by a little. What you can do is to enter into that test mode on the odometer and then keep pressing the button until you get to the digital speedo and it will tell you how fast you are going to compare. __________________ BUILD 2 IN PROGRESS

March 3rd, 2010, 03:07 PM	#3
Teknicz Regular 99 mustang cobra Join Date: Nov 2009 Location: Orlando Posts: 206 iTrader: 0 reviews	test mode?? yea no gears atleast i dont kno if the owners before installed any. But yea the gps is off by a little,but yea i learned it on the freeway comin home from miami where i bought it. my car was goin 100 while my dad was crusing at 70 lol.. and i was wayy to slow when i was at 70 __________________ NO CATS NO GLORY SLP LOUDMOUTH FTW MM Cobra Club #57

March 3rd, 2010, 05:45 PM	#4
wraitherx Moderator '99 SVT Cobra Join Date: Nov 2006 Location: Virginia Beach, VA Posts: 9,568 iTrader: 11 reviews	check this out for the test mode Mustangworld HEC Instrument Cluster Diagnostics __________________ BUILD 2 IN PROGRESS

March 3rd, 2010, 05:49 PM	#5
Justdoit04 Regular 2003 Mustang GT Track Virgin Join Date: Apr 2009 Location: Manassas,VA Posts: 371 iTrader: 3 reviews	haha I'd contact the previous owner if you can ... thats significantly off ... need to get the speedometer recalibrated ... maybe the previously owner had it tuned for the set up they had on it __________________ White Mustang Crew Founder "White Power!" as said by Dave Chappelle Safi is a liar ... Mods: Interior Matching Custom Corbeau CR1 Racing seats

March 3rd, 2010, 05:51 PM	#6
Teknicz Regular 99 mustang cobra Join Date: Nov 2009 Location: Orlando Posts: 206 iTrader: 0 reviews	You freaking rock guy! __________________ NO CATS NO GLORY SLP LOUDMOUTH FTW MM Cobra Club #57

March 3rd, 2010, 07:01 PM	#7
Doc8224 N/A 4v Guru 2003 Mach 1 Join Date: Oct 2007 Location: Afghanistan Posts: 3,463 Blog Entries: 2 iTrader: 1 reviews	what tire sizes do you have? and I agree the previous owner could have done the speedo recalibration to different gears then pulled the gears before he sold the car __________________ Military Crew U.S. Army Aviation Apache's Lead The Way

March 3rd, 2010, 08:34 PM	#10
wraitherx Moderator '99 SVT Cobra Join Date: Nov 2006 Location: Virginia Beach, VA Posts: 9,568 iTrader: 11 reviews	pretty much what they are all saying is sound advice. Only thing that I was saying is not to go by what the GPS is saying since they are not meant to determine speed but since you did say that you compared speeds with your dad then yes take it in to get it recalobrated. __________________ BUILD 2 IN PROGRESS

March 3rd, 2010, 09:49 PM	#12
Teknicz Regular 99 mustang cobra Join Date: Nov 2009 Location: Orlando Posts: 206 iTrader: 0 reviews	Thanks for the input guys, but yea im pretty sure. I kno gps is off a mile or so. You can just tell the speedometer isnt right its too slow than how fast its goin.. maybe he did that with the gears, because i asked the guy i brought em from he said it stock when i first picked it up. It has the 03 cobra rims which is 275 width stock really.. but yea i appreciate the advice guys __________________ NO CATS NO GLORY SLP LOUDMOUTH FTW MM Cobra Club #57

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

Threads Similar to: speedometer is off
Thread	Thread Starter	Forum	Replies	Last Post
Speedometer Help Please!!!	blue_mustang02_gt	Audio/Video	1	February 28th, 2010 08:13 PM
speedometer	cobra97	Modular Mustangs	5	November 2nd, 2008 02:07 AM
Speedometer	djh1286	V6 Mustangs	12	January 5th, 2008 02:09 AM
Speedometer	cdesha	96-98	6	August 15th, 2007 01:11 AM
Speedometer	Arhilion	96-98	8	May 23rd, 2007 07:36 AM

All times are GMT -4. The time now is 05:12 PM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.