Going from the factory 18" to 22". 275 45 22.

They will put my speedo off about 3%.

Will my shift points change or notice a difference ?

 

A little bit...get a speedometer corrector or a tuner with speedometer adjust and youll be good to go

 

Dealer will do it for $120. To change a menu. Take 10 seconds.

 

Does the hypertec have to stay plugged in? Can I help my fathers also?

 

Check the Forscan thread. If you're paying a dealer why not buy the adapter, do it yourself and have the tools for,later use.

I think the hyper tech, like most, get married to a vehicle and can be used in in,y that vehicle. Once you're done and return the vehicle to stock it can be used on a different vehicle.

 

The dealer can not correct the speedometer or shift points, FORScan can correct the speedometer but can not correct the shift points. The only way to change both shift point and speedometer is to buy a Hypertech programmer.

I have increased my tire size from 32" to 34.6" (5% difference) and did not notice any negative side effect due to the shift point being off so I went with correcting my speedometer only with FORScan.

 

I might be mistaken but I would think the shift points would be automatically be adjusted with a correct speedo?

 

Incorrect, the Speedo in controlled by the BCM (Body Control Module) and the Transmission is controlled by the PCM (Powertrain Control Module). FORScan can not access the PCM, it can only access the BCM. Hypertech modifies both computers.

 

And now back to being confused.

 

Figured the speedo would know RPMs for the wheels and motor and miles.