How to Calibrate Speedometer for Bigger Tires F150
If you’ve added bigger tires to your F150, then you know that the speedometer is now reading inaccurately. The good news is, there’s an easy fix for this problem- all you need is a GPS unit and a little bit of time.
- Jack up your truck and remove the tire
- Find the speedometer gear housing on the differential and remove the cover
- With a small screwdriver, pry out the old speedometer gear
- Take note of how it is positioned in relation to the driven gear before removing it so you can install the new one in the same way
- Install the new speedometer gear, being sure to line it up correctly with the driven gear, and replace the cover
- Lower your truck back down and reinstall the tire

Credit: www.roughcountry.com
Can You Calibrate a Speedometer After Bigger Tires?
If you have bigger tires on your car, you may need to calibrate your speedometer so that it accurately reflects your new driving speed. This can be done by following a few simple steps.
First, find a flat, level stretch of road where you can drive uninterrupted for at least a mile.
Start from a stop and then accelerate to your usual driving speed. Once you’ve reached this speed, note the reading on your speedometer. This is your current calibration reading.
Next, use a GPS device or phone app to measure your actual speed. If you’re off by more than a few mph, then you’ll need to adjust your speedometer accordingly. To do this, simply multiply your current calibration reading by the ratio of your actual speed to the reading on your speedometer.
For example, if you were actually going 60 mph but your speedometer said 50 mph, then you would multiply 50 by (60/50), which equals 60. This means that 60 would now be considered “0” on your new scale and all other readings would be adjusted accordingly.
Once you’ve calibrated your speedometer, make sure to recheck it periodically – especially if you change tires again – to ensure that it continues to give accurate readings.
How Much Does It Cost to Recalibrate the Speedometer?
There is no definitive answer to this question as the cost will vary depending on the make and model of your car, as well as the specific speedometer that needs to be recalibrated. However, you can expect to pay anywhere from $50 to $200 for professional speedometer calibration services. If you have a older car or one with a more complex speedometer system, then the cost may be on the higher end of this range.
Additionally, some independent mechanic shops may charge less than what dealerships would charge for the same service.
How Do You Calculate Speed With Bigger Tires?
It’s actually pretty simple to calculate speed with bigger tires. Just take the circumference of the tire and multiply it by the rotations per minute (RPM). This will give you your speed in miles per hour.
So, for example, if you have a 31-inch tire and you’re spinning it at 1000 RPM, your speed would be:
31 inches x 1000 RPM = 31000 inches/minute
Now we just need to convert from inches/minute to miles/hour.
There are 63,360 inches in a mile, so we can divide our answer by that number:
How Do You Calibrate an Electronic Speedometer?
An electronic speedometer is a device that measures and displays the vehicle’s speed. It is usually located on the instrument panel, near the odometer. Many newer vehicles have electronic speedometers that are integrated into the vehicle’s computer system, while older vehicles may have stand-alone units.
To ensure accurate readings, electronic speedometers need to be calibrated periodically. The frequency of calibration will depend on factors such as how often the vehicle is driven and the type of terrain it is driven on (smooth roads vs. bumpy roads).
There are two main methods for calibrating an electronic speedometer: driving at a known constant speed or using GPS data.
Driving at a known constant speed: This method requires access to a stretch of road where you can drive at a steady pace for several miles without stopping. Once you find such a stretch of road, simply drive at your desired speed for 1-2 miles while monitoring the speedometer reading. If the reading is consistently lower or higher than your actual speed, you will need to adjust the calibration accordingly.
For example, if your car’sspeedometer reads 60 mph when you are actually driving 65 mph, you will need to increase the calibration by 5 mph.
Using GPS data: This method is becoming increasingly popular as it does not require access to a specific stretch of road and can be done anywhere there is an open area with a clear view of the sky (such as in a parking lot). To use this method, simply drive around for 5-10 minutes while monitoring your GPS unit’s readout of your current location/speed.
Forscan ford f150 speedometer calibration due to larger tires size
F150 Speedometer Calibration
If your Ford F-150’s speedometer is inaccurate, you can calibrate it yourself with a few tools and some patience. First, you’ll need to find a level stretch of road where you can accurately measure your speed. Once you have your starting point, drive at a constant speed for one mile while timing yourself with a stopwatch.
Compare this time to the mile marker on the side of the road; if your truck took longer to travel the mile than what is indicated on the marker, then your speedometer is reading too slow and needs to be adjusted.
To fix this, locate the calibration screw on the back of thespeedometer (it will be labeled). Turn the screw clockwise tospeed up the needle, or counterclockwise to slow it down.
Re-measureyour speed after making each adjustment until you have achievedaccuracy.
2022 F150 Speedometer Calibration
2022 F150 Speedometer Calibration: How to calibrate your speedometer for the new model year
If you’re like most truck owners, you probably don’t give your speedometer much thought – that is until it’s time to trade in or sell your vehicle. Then, all of a sudden, the accuracy of your speedometer becomes extremely important.
Fortunately, calibrating your speedometer is a relatively easy process that can be done in just a few minutes.
Here’s what you’ll need:
-A laptop or desktop computer with an internet connection
-A USB flash drive (at least 2GB)
-Your truck’s VIN (vehicle identification number)
And here’s how to do it:
1) Go to Ford’s website and create an account.
2) Once you’re logged in, click on the “Owner” tab and then select “Vehicle Profile.”
3) Enter your truck’s VIN and then click on the “Speedometer Correction Factors” link.
4) Download the appropriate file to your computer. The file will be in ZIP format; double-click it to unzip it.
5) Connect your USB flash drive to your computer and copy the file over.
Make sure that the file is saved as “vehicle_speed_file.scf” – if it isn’t, rename it accordingly.
6) Eject/safely remove the USB drive from your computer and insert it into one of the truck’s USB ports. Pressing any button on the steering wheel will cause the message “Updating Vehicle Settings” to appear on the display; once this message goes away, press and hold down boththe trip odometer reset buttonandthe info buttonfor about five seconds until you hear a chime.
This indicates that the update has been successful!
Hypertech Speedometer Calibrator
A speedometer calibrator is a device that allows you to accurately set the speedometer in your vehicle. This can be important for a number of reasons, including making sure that your speedometer is reading correctly, helping you to avoid speeding tickets, and making sure that your car insurance rates are accurate.
There are a few different types of speedometer calibrators on the market, but the Hypertech Speedometer Calibrator is one of the most popular options.
This device is easy to use and provides accurate results.
How to Adjust Speedometer for Bigger Tires Ram 1500
If you have a Ram 1500 with bigger tires, you may need to adjust your speedometer. Here’s how:
1. Park your truck on level ground and turn off the engine.
2. Find the speedometer cable where it attaches to the transmission. There is a small gear on this cable that meshes with a larger gear inside the transmission.
3. Use a small screwdriver or Allen wrench to loosen the set screw that holds this gear in place.
Do not remove the set screw completely, just loosen it enough so that you can rotate the gear.
4. Rotate the gear until the pointer on your speedometer reads correctly for your new tire size. For example, if you have increased from 31-inch tires to 33-inch tires, you would rotate the gear clockwise two notches (or about 1/8 of an inch).
If you decreased tire size, rotate counterclockwise. 5 Once done, tighten down the set screw and take your truck for a test drive!
Conclusion
If you have bigger tires on your F150, you’ll need to calibrate your speedometer so it’s accurate. Here’s how to do it:
1. Park your truck on level ground and set the emergency brake.
2. Find the tire size information placard, which is usually located on the driver’s side doorjamb or in the owner’s manual. It will list the factory-recommended tire size and pressure for your truck.
3. Inflate all four tires to the pressure listed on the placard using a tire gauge.
Don’t rely on the pressure sensors in your truck, as they may not be accurate.
4. Drive your truck at a steady speed of around 40 mph for one mile without stopping. 5. Check your speedometer against a GPS app or another speedometer to see if it’s reading accurately.
If it’s not, you’ll need to adjust it using these steps:
6. With the engine off, locate the two adjustment screws on top of the instrument cluster behind the lens cover (one screw controls calibration for speeds above 55 mph; one screw controls calibration for speeds below 55 mph).
7a) For digital displays: Use a small flathead screwdriver to turn each adjustment screw until The displayed MPH reading is correct according to GPS or another verified source.
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7b) For analog displays: Use a small flathead screwdriver wrapped with electrical tape (to avoid scratching paint) inserted through an opening in bottom of housing and touch contact point inside housing while gently turning screw clockwise or counterclockwise until pointer is positioned correctly per step 1 instructions.