If you've changed the tire size or gear ratio on your 1994 to 2010 Mustang and don't have
or want a handheld tuner, the Ford Performance Speedometer Recalibration Tool will be the
next best way to correct that speedo on your SN95 or early S197.
Now, this $150 4 wire tool will tap into your manual or automatic Mustang's vehicle speed
sensor and will ultimately help you correct that speedo by using the three numerical dials
within the box itself.
With that said, guys, keep in mind this is not a tuner and will not need to reprogram
the PCM in your Mustang.
Install is not gonna be terribly difficult here, guys, but because it does involve math
and wiring, two things people don't normally like, we're gonna knock this one up to a soft
two out of three wrenches on the difficulty meter with a little bit more detail to come
later in the video.
So if you're watching this video then chances are you've either changed the rear gear or
rear tire size on your '94 to 2010 Mustang and don't have a handheld tuner.
Now, if you do have one of those tuners then you can save your money on this product as
most aftermarket handheld devices will have the ability to alter gear ratio and tire size
independent of one another.
Now, in addition to that, you can also take advantage of those other inherit benefits
that come along with grabbing one of those aftermarket devices.
However, if you do not have a handheld tuner and have no intention on picking one up, then
this product from Ford Performance is certainly worth a look.
Now, again, I'm sure, if you're watching this video then you probably already know the deal
here, and that is altering your gear ratio or changing that tire size can lead to incorrect
speedometer readings, which at best can be annoying and at worst can lead to possible
speeding tickets.
And trust me, guys, the old, "I'm sorry officer, but my speedo is not correct or calibrated,"
that line doesn't always fly.
Trust me on that.
So with that said, Ford Performance came out with their recalibration tool.
And again, this guy is gonna tap in to the VSS sensor on your Mustang and then alter
that signal by using some fancy electronics and these numerical dials shown right here.
Now, I've already popped off the four Phillips head screws to show you guys the dials themselves.
They are numbered, and these are what you're gonna be tweaking to get everything set up
correctly.
Now, Ford does give you three different equations for determining what these numbers should
be set to.
First and foremost, you're gonna wanna divide your old gear ratio by your new gear ratio
and then use that number to set your dials up.
For instance, if you had a 327 and you upgraded to a 373, divide those 2 numbers, which would
give you roughly 0.87 and some change that you'd round up to 0.88.
You're gonna set that dial to 088, and that's pretty much it.
Now, the same goes for tire size.
You're gonna wanna divide the old tire diameter with the new diameter, and that number or
the difference would be the three number formula that you'd set this box to.
The final method does involve a little bit more work, and that's basically driving a
distance of 10 miles, comparing that with what your odometer reads, dividing those numbers,
and again giving you your 3-digit answer to set the box up.
I know it all sounds a little bit confusing, guys.
I totally get that, but Ford Performance does include some detailed instructions with this
kit in addition to the instructions that you can find right here on the site as well.
One important thing to keep in mind here is that 2005 to 2010 manual and automatic Mustangs
out there, if you make a massive or drastic change to your gear ratio, basically 5% or
more, your cruise control will no longer function properly when using this specific tool.
So 355 to a 373, you're gonna be good.
But if you go from like a 327 to a 410, for instance, well, it's gonna be a little too
much for Ford's calibration tool to handle.
And at that point, you need to look into a handheld tuning device to make the proper
or necessary changes.
But, let's quickly graze over the installation.
Again, this one will involve splicing those four wires we've already talked about into
your VSS sensor.
And again, you can find those wires and directions in the package in addition to on the site
here.
I did go soft two out of three wrenches on the difficulty meter because let's face it,
wiring isn't everybody's favorite thing, in addition to factoring in that math or those
equations to keep your speedo dialed in just right.
Altogether again though, it's not the hardest job in the world, just make sure you have
your wiring tools ready to rock and roll and, of course, that calculator if you're horrible
at math like me.
But wrapping this one up, guys, if you don't have a handheld tuner and are looking for
an affordable way to correct the speedometer on your SN95 or early S197, be sure to check
out the recalibration tool from Ford Performance right here at americanmuscle.com.