so i did a compression test on my stock gsr the other day it has 120k miles and all cylinders were between 170-180, i heard stock gsr are suppose to be from like 205-215? i live in colorado and i know for sure all n/a car lose a considerable amount of power up here, anyone else from 5000 ft + know theyre compression levels?

 

as long as the numbers are consistent and dont vary 10-15psi from one another i wouldnt be too worried

 

Those numbers are completely normal, i dont believe altitude affects compression enough to make that much of a difference with it.

 

5000ft=.86

215x.86