It is about 4 years old. 195f. Am on a roadtrip now and temp gauge just started reading a smidge higher than normal. Still within accept able range according to factory service manual. Ir temp gun on aluminum radiator maxing out at 192.5f when Temp gauge reads highest. Aiming gun at white gaffers tape next to inlet. Bare aluminum readings are 40 f less. Black sharpied half of tape. No difference between black and white readings. This morning, after a 3 mile drive, temp gauge reading high, but ir gun on top radiator tank indicated t stat had not yet opened. Was 60 f. Another minute idling and it opened and I got 192.5f reading on top tank. Then This fell to 185f short ly after. I know the temp readings are not alarming but am not sure how well they actually represent true coolant temp. Either temp gauge is just reading different. OOrthe engine is running warmer despite cooler ambients. Phone typing forgive structure. 89 dodge b 250 with a 318 and 35k on rebuild. Opinions?