Any suggestions will be great!

[GhostRider]

Ok, so on the drive home today, we noticed that the speedometer on the new 06 GT, is about 25mph too fast.... It's reading 85, when your only going 65. Any ideas on what might be causing this? The car is used, so my guess is that someone swapped out the old gears and never had it re-tuned. The stock gears should be 3:31's. It doesn't feel like it has 3:55 or anything like that. Other than the crazy speed reading, it's just fine. I thinking that a tune might fix this, but I can't say that for certain. I'm not the best mechanic... Any help would be great! If anyone needs further info, let me know and I'll fill you in. Thanks all!

 

[wickedstangs]

sounds like you might need an SCT Tuner.
Sounds like:
1. the car could has gears and the guy removed the tune to sell his SCT Tuner. In the SCT you can put what gears you have and it will calibrate your speedometer.

 

[2K7GTCS]

Hey, look at that. Super bonus score, since she wanted gears anyway! Yeah, I'm going to guess 4.10's?

Use a GPS to obtain the actual vehicle speed versus RPM, then play with the numbers in a spreadsheet calculator, like this one: Mustang Gearing Calculator @ Mustang Collective

You may also need to factor in the tire size, depending on if they are stock height.

 

[GhostRider]

sounds like you might need an SCT Tuner.
Sounds like:
1. the car could has gears and the guy removed the tune to sell his SCT Tuner. In the SCT you can put what gears you have and it will calibrate your speedometer.

Ok, this is what I was thinking. I think I might just take it in to have it calibrated until I pick up another SCT Tuner for her car. Thanks!


Sent from my iPhone using Tapatalk

 

[GhostRider]

Hey, look at that. Super bonus score, since she wanted gears anyway! Yeah, I'm going to guess 4.10's?

Use a GPS to obtain the actual vehicle speed versus RPM, then play with the numbers in a spreadsheet calculator, like this one: Mustang Gearing Calculator @ Mustang Collective

You may also need to factor in the tire size, depending on if they are stock height.

Ok cool, I never thought of that! Good idea! Thanks Dave!


Sent from my iPhone using Tapatalk

 

[GhostRider]

What do you guys think of this? Cheaper solution to a tuner? What does the 10% mean on the third bullet? ---->

Mustang » 2005-2009 Mustang Accessories & Racing Parts » Ford Racing Parts » Appearance & Misc.

$133.10​

MSRP: $196.00​

Savings: $62.90 (32%)​

Ford Mustang Speed-Dial Speedometer Adjuster

​

Used to correct speedometer because of tire size or gear ratio changes​

• Fits 1994-2004 Mustang manual and automatic transmission
• Fits 2005-2010 Mustang with manual transmission. Will correct speedometer. It has no limit on magnitude of gear ratio change for manual transmission vehicles.
• Fits 2005-2010 Mustang automatic transmission. Will correct speedometer to equivalent of 10% gear ratio change, higher or lower.
  Model(s):
  Mustang
  Part Number(s):
  M-4209ADPT-AC

Rating: Not rated yet
Reviews: (0) Share your thoughts?

Add to Cart​

Reviews​

 

[wickedstangs]

just get a tuner and be done with it...

 

[GhostRider]

just get a tuner and be done with it...

yea, That's what I'm going to do seeing as how I'm going to need it anyways for the CAI and any future mods.