larger tires and speedo recalibration?

[o_mccarroll]

I have heard (and I think there may have been a thread on this) that there is a way the dealer can recalibrate the speedometer through the computer to compensate for larger tires. I would like to go to 285's, but I sure would miss an accurate speedometer. Anybody know anything about this or had it done?

 

[RKHebert]

dealer did my tire size (305/70r16) cal with a drb III programmer. took less than 30 secs. they can only adj. for factory supplied sizes. 647 revolutions per mile was as low as they could set. your rpm's for a 285 is 633. 5531838349922. check it out at www.discounttiredirect.com/tiremath.html

my odo was accurate to within 50-100 ft. per mi. closer than i expected.

 

[ACoyle]

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=17968&highlight=abbot



Try this

 

[drag racer]

You could also use the Abbott pulse ratio adapter, which I believe you can program yourself for just about any size tire. No, I don't have one, but there have been many posts in the past about it.



http://www.abbott-tach.com