I was reading through the FAQ page on Mads Electronics web site and came across this:
Which raised a question... I put a different sized tires on my truck several years ago and had the computer re-flashed a the dealer with the new Revs/mile number so my speedo/odo would read correctly and the auto trans would shift at the right time, etc. If I use a Smarty to reprogram with one of the performance softwares and then later use the Smarty to go back to stock, will it overwrite my previous revs/mile flash with the "stock software from it's memory" and remove my previous revs/mile flash?

If that's the case, then I could never really remove the Smarty and return to where I was before using it without having to pay a dealer to re-flash the correct revs/mile value.

 

This seems to vary among Smarty users.

When going back to stock programming, some trucks lose the tire size and others keep the tire size.

On my particular truck, when I go back to stock, the tire size stays as it was programmed and my speedo stays accurate. I know more trucks that stay accurate than those that lose the tire size.

I wouldn't worry about it because chances are you will always run a Smarty level of some kind anyways. It sucks when you go back to stock for any length of time.

Jeff

 

Out of curiousity.... how did you verify that your truck did not loose the tire size?

 

When I set my tire size, I do it using the GPS mounted on my dash until both the speedo and the GPS read the same. When I go to stock, the speedo continues to read the same as the GPS.

And yes, GPS can be off when it comes to speed and distance but mine has been "tweeked" by someone I know in the military and all the "errors" in this civilian GPS unit have been removed. They say that civilian units can't be adjusted, they can.

Jeff