I have a 02 SLE and a CAI and soon to have PEMs and a high flow cat and full custom exhaust. my question is would a 180 tstat be bad for the motor in the winter or any other time and would it affect my mileage. I know there are many posts about stats but I have never seen anything about the altitude plz help I am looking to do a flush if it needs it and while I am in the mess I would change it to a 180 stat TIA

a 180* stat is perfectly safe to use year round, however i have never seen any information about how altitude would have an affect on its function, if any

Your coolant system is unaffected by barometric (altitude) pressure. It'* a sealed system.