2013 Gearing and Speedo Change

[aso544]

With all the threads out there, i just want to confirm that if you change the gears in your 2013 to 3.73s, Ford can NOT correct the speedo? You will have to use an aftermarket tuner? Anyone have an idea how far off it is...faster or slower?

Thanks

 

[Snoopy49]

 

[Farmer-Ted]

Your speedo will read faster. How much faster? (3.73/3.31)=1.126. Divide whatever speed your speedometer says by 1.126 and that will be your corrected speed.

 

[Marc]

Mike, do you have 373s in your Shelby now?

 

[Farmer-Ted]

Mike, do you have 373s in your Shelby now?

Nope not right now. Maybe down the road a bit though.

 

[Snoopy49]

 

[Planeswalker]

Dropped my car off just now to get 3.73s put in tomorrow.

 

[aso544]

Keep us posted on results...feel free to use this thread

 

[JDJ]

Silly question, with the false reading on the speedo will this also falsely increase mile on the odometer. I looking at going 3.73 but if its going to rack extra mile on the odometer, I will pass on the install.

 

[MNCobra]

Silly question, with the false reading on the speedo will this also falsely increase mile on the odometer. I looking at going 3.73 but if its going to rack extra mile on the odometer, I will pass on the install.

i would love to know this too....i have a hard time believing it will rack up extra miles....in order to add miles to the car you have to actually drive those miles dont you?....but i am not a guru by any means....:rolling:

 

[Snoopy49]

Unless you recalibrate your speedometer, your true speed will be less than the indicated speed. The odometer will register mileage according to the indicated speed.
Example:
10 MPH - 3.31 gears
8.9 MPH - 3.73 gears
Every 8.9 miles, will show as 10 miles on your odometer with 3.73 gears.

 

[shelbysvt]

So then if we had a gear ratio lower than 3.31 we could drive more and it shows up as less?

That sucks for those who go up to 3.73s without a calibration lol.

 

[Snoopy49]

Here is another example of an uncalibrated speedometer and 3.73 gears.
50,000 miles on the odometer equals 44,500 actual miles driven.
That's means your 50,000 mile warranty will run out 5,500 miles early.