How to Calibrate Speedometer for Larger Tires Dodge Ram
If you have recently installed larger tires on your Dodge Ram, you may need to calibrate the speedometer to ensure that it is reading accurately. While there are a few different ways that you can do this, the most common and effective method is to use a GPS device. This will allow you to see how fast you are actually going, and then adjust the speedometer accordingly.
- Park your vehicle on a level surface and set the emergency brake
- Find the speedometer calibration adjustment knob, which is usually located under the dash on the driver’s side of the vehicle
- Use a tire gauge to measure the diameter of each tire at its widest point
- Divide this measurement by 2 to get the radius of each tire
- Multiply this number by 3
- 1416 to get the circumference of each tire in inches
- 6a) For 2005 and newer model year Rams with 5-speed automatic transmission: multiply circumference by 4th gear ratio (usually
- 69) 6b) For all other Rams: multiply circumference by final drive ratio (rear axle) as follows: manual transmission – 3rd gear ratio x
- 69 x
- 50 =
- 345); automatic transmission – overdrive gear ratio x
- 62 x
- 50 =
- This will give you your new tire size’s effect on speedometer reading in percent (+/-)
- Adjust your speedometer according to manufacturer’s instructions using this formula: Newpercentage – old percentage = amount to adjust speedometer

Credit: www.roughcountry.com
Can You Adjust Your Speedometer for Bigger Tires?
If your vehicle came with bigger tires from the factory, then you don’t have to do anything to adjust your speedometer. However, if you’ve installed bigger tires yourself, then you’ll need to make a calibration adjustment so that your speedometer reflects your actual speed.
There are a few different ways that you can go about making this adjustment.
One is to simply drive at a known speed (like 60 mph) and then measure the distance it takes you to travel one mile. If your tires are larger than stock, then it will take less distance to travel one mile and you’ll know by how much you need to adjust your speedometer reading.
Another method is to use a GPS device while driving on the highway.
You can set the GPS to show your actual speed and then compare it to what your speedometer is reading. This will give you a good idea of how much faster or slower your vehicle is really going compared to what the speedometer says.
Either way, once you know by how much yourspeedometer needsto be adjusted, there are a few different ways thatyou can actually make the adjustment itself.
Many newer vehicles have an electronic control module that can be programmed with the new tire size information. For older vehicles, there’s usually a physical cable connecting the speedometer headto the transmission or wheels; this cable canbe loosened and moved slightlyto changethe reading onthe speedometerto matchthe newtire size.
How Do You Calibrate a Speedometer for Different Size Tires?
How to Calibrate Your Speedometer for Different Size Tires
If you’ve ever changed the size of your tires, you know that it can throw off your speedometer. The bigger the change in tire size, the more inaccurate your speedometer becomes.
This is because most vehicles have their speedometers calibrated for the original equipment tires. So, if you’re driving around with different sized tires, your speedometer will be reading incorrectly. But don’t worry, there’s an easy way to calibrate your speedometer for different size tires!
Here’s what you’ll need:
– A GPS unit or smartphone with a built-in GPS (for accuracy)
– A pen and paper (for taking notes)
– Your vehicle’s owner’s manual (for reference)
First, find a flat and level stretch of road where you can drive at a consistent speed without stopping. Start by driving at a steady pace of 35 mph using your GPS unit or smartphone to track your actual speed.
Note down this number. Next, consult your owner’s manual to find out what your car’s stock tire size is supposed to be. Let’s say it’s 225/50R16.
Now look up the circumference of this tire size online (you can use this handy tire size calculator). In our example, the circumference would be approximately 88 inches.
Now that you have both numbers – 35 mph and 88 inches – divide them to get the ratio: 0.395 miles per inch (35 ÷ 88 = 0.395).
This is the number you’ll need to calibrate your speedometer for different size tires!
Whenever you change your tires to a different size, simply multiply this ratio by the new tire’s circumference to get the new calibration number specific for that tire size. So if you switched to 245/45R18 tires, which have a circumference of about 92 inches, multiplying 0.395 by 92 would give you 36 mph as your new calibration number specific for those tires. Then just drive at that same steady pace of 36 mph and note down how fast your speedometer reads; it should now be accurate!
How Do You Calibrate an Electronic Speedometer?
An electronic speedometer is a device that uses sensors to measure the speed of a vehicle. The most common type of electronic speedometer is based on the Doppler effect, which measures how the frequency of a signal changes as it moves toward or away from an observer.
To calibrate an electronic speedometer, first make sure the vehicle is parked on level ground and the tires are inflated to their proper pressure levels.
Next, find a straight, level stretch of road where you can drive at a steady speed for at least one mile without stopping. Once you’re in position, reset your trip odometer to zero and begin driving at your desired calibration speed. For example, if you want to calibrate your speedometer to read 60 mph when you’re actually traveling at 55 mph, then drive at 55 mph for one mile while monitoring your speedometer.
When you’ve traveled one mile at your specified speed, compare the reading on your trip odometer with the reading on your electronic speedometer. If they match, then yourspeedometeris properly calibrated. If not, adjust yourspeedometerto achieve the desired reading and repeat the process until it’s accurate.
How Do You Calculate Speed With Bigger Tires?
When you install bigger tires on your car, it will affect the speedometer reading. This is because the larger circumference of the tire means that it will travel a greater distance than the smaller tire in one revolution. To account for this, you need to calculate the new speed of the vehicle with the bigger tires.
There are a few different ways that you can do this calculation, but one of the most common is to use a ratio. To find the ratio, you simply divide the new tire size by the old tire size. For example, if you had a 30-inch diameter tire and replaced it with a 35-inch diameter tire, your ratio would be 35/30=1.17.
You would then multiply your original speed by 1.17 to get your new speed with the bigger tires.
Another way to calculate your new speed is to use something called “mph per tick.” This takes into account not only the difference in circumference between the two tires, but also how fast each one rotates.
To find mph per tick, you would divide 5280 (the number of feet in a mile) by the circumference of both tires (in inches). So, continuing with our example above, we would have 5280/(35*3)=85 ticks per mile for our new 35-inch tire. For our old 30-inch tire, we would have had 5280/(30*3)=95 ticks per mile.
Therefore, our new speed with bigger tires installed would be 95*(35/30)=85 mph – an increase of 8%.
Of course, these calculations are all based on ideal conditions and there are other factors that can affect your actual top speed – such as wind resistance and engine power – so don’t take them as gospel! But they should give you a good idea of what sort of speeds you can expect from larger diameter tires on your car.
Speedometer Calibration – Adjust for Bigger Tires – Accurate Shifting & Fuel Economy
Hypertech Speedometer Calibrator
If you’re looking for a way to calibrate your speedometer, the Hypertech Speedometer Calibrator is a great option. This device is easy to use and it’s very accurate. It’s also small and compact, so it’s easy to take with you on the go.
The Hypertech Speedometer Calibrator can be used on most vehicles with electronic speedometers. It works by sending a signal to the vehicle’s computer that adjusts the speedometer reading to match the actual speed of the vehicle. This is great for those who have aftermarket tires or wheels that change the circumference of the tire, which can cause the speedometer to read incorrectly.
To use the device, simply plug it into your vehicle’s OBD-II port (this is usually located under the dash) and follow the prompts on the screen. The whole process takes just a few minutes and doesn’t require any tools or special knowledge. Once you’re done, your speedometer will be accurately calibrated and you’ll never have to worry about it being off again!
4Th Gen Ram Speedometer Calibration
If you own a 4th generation Ram truck, you may have noticed that the speedometer is inaccurate. This is a common issue that can be easily fixed with a little bit of calibration.
There are two ways that you can calibrate your speedometer.
The first is to do it manually. This can be done by using a GPS device or by timing yourself over a known distance. To do this, simply drive at a constant speed for one mile and then compare your actual speed to the speed shown on the speedometer.
If it is off by more than 2%, you will need to adjust it.
The second way to calibrate your speedometer is to use an electronic device called a Superchips Flashpaq tuner. This tuner will not only recalibrate your speedometer, but it will also improve your fuel economy and optimize your engine performance.
It is a relatively simple process and only takes a few minutes to complete.
Whichever method you choose, calibrating your 4th generation Ram’s speedometer is easy to do and well worth the time and effort. Your truck will thank you for it!
How to Calibrate Speedometer for Bigger Tires
If you’ve installed larger tires on your vehicle, you may have noticed that your speedometer is no longer accurate. This is because the larger tires cause your vehicle to travel a greater distance per revolution than it did with the smaller tires. As a result, your speedometer will read lower than your actual speed.
There are a few different ways that you can calibrate your speedometer for bigger tires. One option is to install a GPS-based speedometer correction device. This type of device uses GPS signals to calculate your actual speed and then adjusts the reading on your speedometer accordingly.
Another option is to recalibrate your speedometer manually. This can be done by driving at a known, constant speed (such as 55 mph) and then measuring the distance that you travel in a specific amount of time (such as one mile). Once you have this information, you can use a simple formula to calculate the correct reading for your new tire size.
No matter which method you choose, it’s important to make sure that your speedometer is accurately calibrated so that you can avoid getting speeding tickets or getting into accidents.
2022 Ram 2500 Speedometer Calibration
The 2022 Ram 2500 Speedometer Calibration is a new feature that allows drivers to calibrate their speedometers for more accurate readings. This is especially helpful when driving in different weather conditions or on different road surfaces. The calibration process is simple and only takes a few minutes to complete.
Conclusion
If you have larger tires on your Dodge Ram, you may need to calibrate your speedometer. Here’s how:
1. Park your Ram on level ground and set the parking brake.
Put a wheel chock behind one of the rear wheels, just to be safe.
2. Use a tape measure to find the circumference of one of the tires. You can do this by measuring from one end of the tire tread to the other, around the middle of the tire.
Alternatively, you can look up the circumference online for your specific tire size.
3. Enter this information into a speedometer calibration calculator (you can find these online). This will tell you how much you need to adjust your speedometer readings by.
For example, if it says you need to subtract 10%, that means your speedometer is reading 10% too fast ( meaning that when it says you’re going 60 mph, you’re actually only going 54 mph).
4. Adjust your speedometer accordingly using the button or knob on the dash (this may be labeled “odometer” or “trip odometer”). On some Rams, there may be two buttons – one for setting overall mileage and another for resetting trip mileage back to zero – so make sure you press the right one!