I just upgraded my tires to 285/70r17 toyo open country at2 and added a 2.5 suspension lift from rough country. My question is do I need to get a flashpaq or flashcal to calibrate for the larger tire with added weight? I'm not sure if my tires are throwing my speedometer but i'm sure it has to be a little bit correct?

 

Any height change to taller or shorter tires will affect the speedo/odo. Is it enough to worry about?

Stock 29" to new 33"? Get one.
Stock 32" to new 33"? Get one if you want the other features.

 

Stock 32 to 33.

 

I'd get one to make sure everything is adjusted accordingly but mainly for the other features. A little biased since I just got mine in the mail