Recalibrating speedometer

[smkt404]

When replacing 20 inch wheels 275 55 R20 with 285 45 R22 do you need to Recalibate?

 

[Jedi9]

If the diameter changed

 

[smkt404]

If the diameter changed

Who can recalibrate it or can I do it?

 

[DEG]

I wouldn't worry about it with that very minor change in diameter. The change in height is only about 2/10s of an inch. At 70 mph your actual speed with be 70.4 mph.

According to my tire size calculator the 275-55-20 are 31.9 inches diameter. The 285-45-22 are 32.1 in diameter.

 

[Redz72]

AlfaODB or JScan apps can do it. I use JScan because it’s Apple compatible.

 

[CHeYeNNe71]

I wouldn't worry about it

 

[Darksteel165]

I wouldn't worry about it with that very minor change in diameter. The change in height is only about 2/10s of an inch. At 70 mph your actual speed with be 70.4 mph.

According to my tire size calculator the 275-55-20 are 31.9 inches diameter. The 285-45-22 are 32.1 in diameter.

This is also assuming it was correct from the factory which I don't think all of them are. Mine was off from the factory with oem 22s.

 

[Jedi9]

At that difference I wouldn't bother. Tires usually read smaller dia after being loaded. Best way to check run a speedometer app and see what the difference is from your speedometer.

 

[Machinetools1]

Has anyone used a Hypertech In-Line Speedometer Calibrator (19-22 RAM 1500). I was planning on purchasing one and installing put wanted to know if anyone has used one yet?

 

[awesomedudekj]

Has anyone used a Hypertech In-Line Speedometer Calibrator (19-22 RAM 1500). I was planning on purchasing one and installing put wanted to know if anyone has used one yet?

I think you'll find that most people use alfaobd, jscan, or tazer. You'll be able to make the tire size adjustment and much more, plus I think you'll end up spending less.

 

[Darksteel165]

I think you'll find that most people use alfaobd, jscan, or tazer. You'll be able to make the tire size adjustment and much more, plus I think you'll end up spending less.

Yep, pay less get way more. A no brainer.

 

[Machinetools1]

Thanks for the input, Glad I asked as I guess the Hypertech In-Line Speedometer Calibrator (19-22 RAM 1500) is not California legal. Thanks again.

 

[CHeYeNNe71]

Thanks for the input, Glad I asked as I guess the Hypertech In-Line Speedometer Calibrator (19-22 RAM 1500) is not California legal. Thanks again.

That's hilarious, something so simple and doesn't do much.

 

[Machinetools1]

Agreed, Cali is great for sightseeing, but anything else....Well.