FORscan Speedo Recalibration & Tire Sizing

[SR56]

Bringing this over from the Mustang6g community since I've seen folks asking about tire/wheel sizes and speedo issues. You should be able to adjust Forscan speedo calibration using the calculator link. Also including info on how to match up the revolutions per mile if you'd prefer to not mess with recalibration.

*Disclosure: I am NOT a tire, wheel, or FORScan expert. I have not used the device to make these adjustments. Do so at your own risk.

Ford As-Built Tire Calculator

Tire Size Comparison

Discount Tire Conversion

FORScan Forum - How to Adjust Tire Size (thread)

Correct Your Speedometer Error - No Flash or Tune Required (FORScan thread from Mustang6g user Spart)

Tire Rack also has all the specs on every tire for actual tread width and revolutions per mile. Keep in mind that not every tire with a listed width is the same. You can have a "295" tire from different brands with a 1" to 2" tread width difference.

If you click on "Specs" on the tire model info page you'll have access to all this info:


This is what it looks like when you select multiple tires to compare and then click on the "Detailed Specifications" + button:

 

[Big Turk]

If this information is valid for an ST, this may be a good post to make a sticky.

 

[SR56]

If this information is valid for an ST, this may be a good post to make a sticky.

Don't see why it shouldn't be. Per the As-Built Calculator, they have a section for 2020+ Explorer. The other information contained in threads can be useful as to how others were able to adjust their Fords. FORScan adjustments have been common for Mustangs, F150, Edge, etc for a while now. All of this info should be helpful for us to at least figure out the pathway to ensure proper calibration. Just need someone to test it out that is familiar with using the tool.

 

[Snoopyto]

I just got my 23 ST and already noted my speedometer is about 2 MPH under actual. I don’t have the vehicle right now, wife in Florida, but I do have as built and I guess I need figure 1) if as built has the right size programmed. 2) if so, figure out which way it needs to mod. I am thinking the number needs to smaller. 3) than question. E comes how much.

 

[SR56]

I just got my 23 ST and already noted my speedometer is about 2 MPH under actual. I don’t have the vehicle right now, wife in Florida, but I do have as built and I guess I need figure 1) if as built has the right size programmed. 2) if so, figure out which way it needs to mod. I am thinking the number needs to smaller. 3) than question. E comes how much.

I've noticed I'm reading 2 MPH higher that speedo at highway speed. Radar GPS and Waze both confirming. When trying to be "safe" cruising I set at 79 on the speedo for cruise. Looks like I'm actually at 81, though.

Interesting that on the low end 30 and under the speedo is a little slow so I need to set at 31 to be GPS 30.

I've never messed with forscan but I guess it's time to learn!



Sent from my SM-N986U using Tapatalk

 

[Snoopyto]

Sooo, I pulled my as-built and used the ForScan to calculate the hex numbers. It programs on to two different lines. One line is not correct based on the calculation. I guess Sunday, I will get to play with it on the truck