Hi everyone,
I bought my Ram almost 2 years ago and it came with a set of 20" tires. I have since replaced the 20" with 265-70-17". And of course the speedometer is now reading 3 mph faster than I'm actually going. It may not sound like much but it will make a difference eventually.
My question is, does anyone know if this is corrected by different gearing in the transfer case ? Or can it be calibrated electronically. If it's gearing, then how do I come up with the correct gears ( # of teeth ) ?
Thanks for reading this
Roger

 

You can either pay the dealer to reprogram the PCM for the correct tire diameter or you can buy a programmer such as a Diablosport Predator or Superchips and do it yourself. It is all electronic, no speedo cable or gear to change.

 

lxman1,
Thanks for the fast response. I'll have to find out how much a programmer is versus how much I will ever use it after this. Or just PAY THE DEALER. I don't even like typing those words !!!
Thanks again,
Roger

 

Get a tuner! Either a Superchips or Diablo will do wonders with an '05. Firmer transmission shifts, more HP & Torque, better fuel economy and the ability to read and clear DTCs are just a few benefits besides being able to re-calibrate for tire size changes...

 

Thanks HammerZ71,
Any idea what the prices are for those ? And where is the best place to get them ?

Roger