cooling problem...thermostat?

my jeep heats worth of shit in the winter, and overheats in the summer...the guy i bought it off of, says he doesnt remember changing it, but he thinks he did it, so if he changed it he says its a 180 degree thermostat, and if not its the stock 195....i was thinkin about putting a 160 degree thermostat in it, and my friend who has an XJ, says its a bad idea, because the I6s were made to run at 210 degrees all day...i cant have this thing overheating, its a work vehicle, daily driver, and toy......the coolant has been changed, and im not sure about the waterpump....what thermostat should i go with??? :helpme:

195 is stock, i live in palm springs cal, today it is over 105 an my heep runs at 200 - 210 , get the right t-stat an flush your rad, then use a 50/50 anti-freeze... i went to dealer because i want the hole in it for my closed sysm.

Dont run anything else than 195. Even changing from a 180*F to a 160*F thermostat will increase your engine wear by 4 times! Not to mention the whole time it will be running rich costing you mileage as the O2 sensor wont even be read by the ECU as it is waiting for it to warm up.
Also running a colder thermostat WILL NOT stop over heating at all. Once a thermostat is open, no matter what the temperature it opens at, it is running the same amount of coolant through the radiator.
Fit a new 195 themostat and then take a look at your water pump and radiator if it does not get it running between 195 and 220.