I was playing around with my predator to adjust for the new tires, they were slightly different size. In doing so I came to the conclusion that you could essentially trick teh computer into think you had far less mileage then you actually do. By changing your tire size to the smallest setting you effectively change the way the computer sees the road. Your speedometer wont change because its mechanical but your odometer, trip meter, fuel economy and all of those other figures will be off. Changing your axle ratio setting could also do the same thing. I dont know what the side effects are, other then your odometer and the other computer based trip stuff being wrong.

Tranny shifting will be off.

i didnt notice a change....that was at WOT though

i believe this is essentially illegal? Odometer fraud (knowingly is the key though) If you had no idea the whole time (if someone found out that is) you'd be ok. But obviously I wouldn't do this, too much risk Id say if you ever wanted to sell the beast. Good post though

plus youd never know when to maintenance at proper interval,s unless you tracked real mileage on separate unit.

Wow that's wierd

Actually your speedometer will be off also. Speed is determined by the pulses coming from the trans, the diameter change perturbs the calculation so that the speedo and odometer count a different number of pulses per rev. They are tied together. The last mechanical part to the speedo is the driven gear on to the speed sensor. The cluster recieves one input harness an 2 pass through harnesses, although I have not actually verified the in and outputs.