i have my HPP3 shift points set high, and in the winter my truck would 2-3 shift at about 80-90 mph. now in the spring, the 2-3 shift is at 60 mph, way too soon for me. is it the warm weather? or does the truck need to be programmed again? probably the 1st

 

I know that I programmed my new tire size 295 45 18's and with shift points at +6 for 1-2 and +10 for 2-3, it felt like factory until I just decided to deal with my speedo being off. When I went with stock tire height, it shifted properly. I guess they need to boost up shift points to compensate for the calibration of new tire size. Or maybe there is a problem and mine is not calibrating the shift points for the new tires. I don't know. But that is the only thing I have had to deal with about shifting half-***.

 

i still have the same stock tires from day one. a month or two ago, it would shift late, now it is shifting way too early. and it varies from day to day. i'm coming to the conclusion that it is the humidity and temp. does this sound right? can these environmental factors alter this shift points? my HPP3 has been set at +3, +12 for the longest time and it has worked well for me in the past. so what's the story?

 

My truck does seem to have it's good days and bad days. But I haven't noticed the shift points changing at all, definently not by 10-15 mph. I'd try reprogramming it.