Originally Posted by EVL WRX

Example, on my old GTR, I had a Power FC which displayed water temp. The needle on the stock gauge didn't move until the water temp got to about 60 degrees, and when it was up to temp the PFC could show a 10 degree difference and the stock gauge looked like it didn't move (or it moved so little it didn't help).

IMO the stock water temp gauges are not accurate enough for full reliance on them..