Speed adjustment for larger tires

[Jonesey]

I purchased a new 2020 RAM 1500 from the dealer. They put a small lift and 35" wheels on it. Because of the new wheels my speed, miles, MPG are all off. I purchased two different devices to adjust the speed and have the same problem with both. When I use the device to adjust the speed it disables several features and functions of the truck. The most recent was the Superchip Calibrator but when I put in the Bypass it disables front and rear sensors, XM radio and more. How do I work around this. Can I change the speed and then just take the bypass out and plug back in to the factory plugs or will that cause problems with the adjustments I made to the computer?

 

[securityguy]

If your dealer installed the tires and lift, they should recalibrate it a no charge. Call and ask.

 

[Jonesey]

Yes, I thought the same thing and was told they did not have the ability to recalibrate it. Something about not having the machine to do it. Which maybe makes sense since all the things I have seen require some type of programmer that copies the VIN and information into the programmer. I don't know. They couldn't do it.

 

[ekaz]

Yes, I thought the same thing and was told they did not have the ability to recalibrate it. Something about not having the machine to do it. Which maybe makes sense since all the things I have seen require some type of programmer that copies the VIN and information into the programmer. I don't know. They couldn't do it.

They have the tool, just either don't know or don't want to do it.

 

[Nels]

They have the tool, just either don't know or don't want to do it.

They don't know is likley the issue. My 33's were purchased from and installed by my dealer. They were supposed to recalibrate but said my tire size doesn't come up as a selection in whatever system they use.

 

[5thGenLoco]

They sold you a vehicle with an incorrect speedometer calibration? My guess is there are some legal issues there. Are you supposed to just guess at how fast you're going? Or how far you have actually gone? Like others said, they are either too ignorant or unwilling to fix the issue. They need to correct the problem, end of story.

 

[Nels]

They sold you a vehicle with an incorrect speedometer calibration? My guess is there are some legal issues there. Are you supposed to just guess at how fast you're going? Or how far you have actually gone? Like others said, they are either too ignorant or unwilling to fix the issue. They need to correct the problem, end of story.

No. Sorry if i didnt communicate clearly. When i bought the teuck it had stock tire size. I replaced the tires 6 months later. Bought the tires through the dealer on the buy 3 get one for $1 sale. Dealer installed them.

 

[securityguy]

No. Sorry if i didnt communicate clearly. When i bought the teuck it had stock tire size. I replaced the tires 6 months later. Bought the tires through the dealer on the buy 3 get one for $1 sale. Dealer installed them.

They should still calibrate them!

 

[Nels]

I agree. But they dont know how to if the tire size isnt in the menu of their software. I had also asked the another Ram dealer in my area before ordering the tires. Thst dealer said they couldn't do it at all, and auggested i would need to buy my own recalibration tool. I havent done that yet, but probably will if at some point i start towing a heavier trailer. Im really not concerned about the incorrect speed of 2-3 mph. Im more concerned about shift points, etc but really havent noticed anything too problematic.

 

[5thGenLoco]

No. Sorry if i didnt communicate clearly. When i bought the teuck it had stock tire size. I replaced the tires 6 months later. Bought the tires through the dealer on the buy 3 get one for $1 sale. Dealer installed them.

In that case, it's on you to calibrate the speedo. I've never had a tire shop ever recalibrate after a tire swap.