If your gonna do it just do it. Posting on the Internet that you are thinking of doing it isn't very smart.

 

You'll go longer between oil change intervals and reduce the lifespan of the vehicle, how is that satisfying? The vehicle will have traveled the same distance, but it'll look like less on the odometer, so you end up going further between maintenance schedules. (I think, I don't do numbers at all)

Not to mention what everyone else said. Remind me never to buy an 06 Legend Lime GT if I'm in the market...

 

I'm pretty sure that the speedo and odometer are all based on the gear setting AND the tire revs/mile so you can adjust both and you can wear out the car faster than it'll appear by adjusting only the gear setting. Of course, WHY you'd really bother to throw off your onboard like that is beyond me. YOU'D know that you had more miles on the car than what the odometer says and that alone would drive me nutz.

 

Yes, except bigger tires serve a purpose, whereas purposeful mis-adjustment of the speedo to affect the odometer shows intent. Big no no OP.

 

Morals, not so much.

 

Whoa, this got a lot of attention in 2 hours. The question was if it even worked. And for mustangs as long as all cars and trucks runnin a bigger than stock tire??? Fraud correct?

 

Yeah, OD and speedo adjustments are controlled by the same settings in the tune. tire revs per mile and gear ratio could be adjusted so the miles actually driven don't show up on the ODO, this would be dishonest and a crime when you go to sell, I don't know anyone who has been prosecuted, but still...
On your year, technically you could also go to the junkyard and pick up a low mileage gauge cluster and simply replace it when you go to sell, since on the 2005-2009, the ODO mileage is stored in the gauge cluster and not on the PCM... also a crime and douche-baggy to do.

 

You put something like that out here and hell yes it is going to attract attention. What did you think was going to happen? A big pat on the back? I have driven trucks with slightly larger tires and yes I had the speedometer corrected. Nuke posted my feelings on that one. I am actually glad that enough people in here had the ***** to call you out on it.

 

Where's the satisfaction in "My Mustang broke down at 130,000 miles instead of 170,000?"

 

I see your points. If I do plan ok keeping the car ( which I do) then it's a pointless matter. I was curious if this was possible considering I drove a ways with the speedo putting extra on the clock. The idea came from last night on the news they took 4 brand new cars around a race track and all had a different odometer reading! Which shocked the crap out of me considering mileage on a car effects pretty much everything which is te sad truth....