Speedometer Woes

[Baby Ollie]

First off, let me say that my car is a completely stock 2000 GS. Stock LS Mesh wheels, good tread on the tires, nothing that should distort the speedometer reading. I am aware that most cars will read a few MPH above your actual speed, and a few MPH discrepancy wouldn't bother me at all. However, my GPS consistently shows that my speedometer is reading 9-10MPH slower that the actual speed of my car (assuming the GPS is correct). The discrepancy really kicks in at the 65-83 MPH mark, and then returns to mostly accurate readings. I've included a table to give you an idea of what I'm dealing with. The speed on the right is my speedometer, and the speed on the left is my GPS. The deviation is listed on the far left.

Speedometer........GPS................Deviation

50.............................48.................+2
55.............................52.................+3
60.............................55/56............+4/5
65.............................59/60............+5/6
70.............................63/64............+6/7
75.............................58/59............+6/7
80.............................72/73............+7/8
85.............................82.................+3


Anyone know why I would have the most issues at the 65-80 MPH mark? I have tested the GPS in my girlfriends car (2002 Focus) which is almost always spot-on regardless of speed, and my dad's car (2010 Legacy) which is constant 2-3MPH deviation regardless of speed.

I do a lot of driving over Snoqualmie Pass (I-90) and the speed limit most of the way is 70MPH. It's really annoying to not feel like I can trust my speedometer to get my true speed. I tend to error on the side of caution though, since as a 22 year old male, I cannot afford moving violations on my record.

I'm praying that someone here will have an easy, simple fix. I am mostly car illiterate, and don't feel like shelling over a few hundred bucks to a mechanic for something like this.

Thanks for any and all help!

 

[99tegjawn]

Your deviation from your reading shouldn't change that drastically it should be pretty consistent. Unless your flux capacitor is broken then you may have to alleviate the pressure on the omg valve. Have a buddy do 60 then match his speed and look at the speedo.


Sent from my iPhone using Tapatalk

 

[Excitable Kid]

Mines about 5+/- mph off after it hits like 65 mph. That's normal, though.

Here's your fix: http://www.clubintegra.com/board/showthread.php?t=56519

 

[Baby Ollie]

Your deviation from your reading shouldn't change that drastically it should be pretty consistent. Unless your flux capacitor is broken then you may have to alleviate the pressure on the omg valve. Have a buddy do 60 then match his speed and look at the speedo.


Sent from my iPhone using Tapatalk

I said I'm automobile illiterate, not of the gentler sex.

 

[Baby Ollie]

Mines about 5+/- mph off after it hits like 65 mph. That's normal, though.

Here's your fix: http://www.clubintegra.com/board/showthread.php?t=56519

But if I do that, my spedo will be off at the other speeds.

 

[Excitable Kid]

Who knows. You haven't tried. And that's the only fix I know of. Either you stick with your woes or you do the fix. Capisce?

 

[Nick_C78]

Honestly, I wouldn't do the remove the needle trick. It is not an accurate way to calibrate your speedo at all. The best thing for you to do is to swap the speedo in your cluster for a working one, and just adjust the miles to what yours is suppose to be. That is what I have done in the past and it always worked the best. I tried to do the stupid needle thing before(several attempts) and it ended up all weird/breaking stuff because it is so delicate.

 

[R13]

Your deviation from your reading shouldn't change that drastically it should be pretty consistent. Unless your flux capacitor is broken then you may have to alleviate the pressure on the omg valve.

:lol: