i did the search and the only 3rd gen item that came up was for someone who has an auto trans. is it different for a manual trans? what do i do? on my jeep i had to change the speedo gear in the transfer case. do i do that for my truck too? running 295/70/17 nitto's now and off by at least 5 mph, but probably more like 10 mph.

 

It takes a programmer (Dealer DBIII) to set revs per mile. They'll like charge about $50 for this service so set it up so you can get the setting more than one time, because it will take at least two attempts to get it right.

Have the dealer set the tire maker revs/mile number into the pinion factor area. Then take it out for a spin with a GPS with the understanding that you might need a second adjustment. Drive indicated 60mph and see what the GPS says. If it says 62.5, you have a 4% error. Multiply the initial revs/mile number by .96 and then have the dealer put in the result. This should get you very close.

Or buy a Smarty unit and do it yourself. Consider the $50 saved as the first payback for a new Smarty unit.

 

I doubt 295s are off by that much. My 35s threw it off by 6 miles/hour at 60. Like said above Dealer can reflash(but only up to a certain size), Smarty can too, or Edge J/A can calculate MPH for different size tires too.

 

my service guy had 35 on his and i think he said they could adj up to 34.? so it will be close

 

I think that is just in the preset sizes. When I had the dealer do mine there were a few preset sizes but there was another menu where you can set the revs per mile had them do mine twice was still a little off got a downloader triple dog or smarty so you can play with it yourself. Goin to the dealer to wait for them to charge you to get it wrong is a bi pain in the a**

 

problem with buying the smarty is i already have enough power for what i do so i can't see justifying the purchase right now. ill check what the dealer has to say today. thanks.