whats the largest tire size jody can calibrate for anyone know?

 

The lowest revs per mile the pcm will interpret is 601.

A LT315/75R16/D BF Goodrich AT is 598 revs per mile and its 34.8" so if you programmed for it the PCM would use 601

One of the truspeed boxes will let you program to anything you want.

 

I dont think jody can recalibrate your speedo through the chip. The only two ways i know to recalibrate is at fords with there tool, and through a box like the truspeed. Ford can only do up to a 35. The truspeeds are pretty much unlimited.

 

Yes, You can not reprogram tire size in a chip... Ford can up to 35"s and then there is the true speed, but I guess you only get to recal the true speed 4 times??? Kinda dumb if thats true...

 

My accuspeed it has a potientometer inside that you spin to adjust your speedo. I did it while i was driving lol. IDK about the truspeed units.

 

The tire size can be allowed for in the programming. Larger tire sizes over 33's can make the shift points off causing the speedo to be off as well. When you go to calculate fuel mileage it will be off if your speedo is not recalibrated. Your shift points are based on Speed and throttle position. It would call for a custom program based on the tire size. The only down side of doing it the programming is if you ever change tire sizes again you will need your chip reprogammed each time you change. A dealership can reprogram up to 33's. This is done through the ABS module. Some don't do it, so I would call them first. Anything over that it is just best to get a truespeed. A truespeed is going to be roughing the same as custom programming for the larger tire size. You can also stack the truespeed if need be for even larger tire sizes.

Diane

 

Thanks for the info. I think ill get the truespeed cause i change tires all the time between my 37's and my 33"s for winter. OH and as soon as my tax return gets here ill be ordering a chip so i look forward to talking to you soon.