Well i think the bars in the stock guage are 30 degrees apart, so i believe my car was running at 190, which was the 2nd bar, but after running it pretty hard, it would run up to the 3rd or 4th bar, so i figured i had to change the stat out. so i got a 160, figuring it would make it run cooler. i had a radiator that i got from a friend which is a 4 core. now i have it running pretty constant at the first bar, no matter how i run it. I have another question for everyone here, how can i tell for sure if a heater core is going out? i thought mine was replaced before i got the car. thanks!