My truck has always cruised with an engine temp of 185 degrees. In the last couple of months, I've noticed it now cruises at 190. Not much difference, but a difference none the less. My concern is that it's a prelude to some future problem. The cooling system is full and the coolant looks like it just came out of the bottle. I've drained and replaced the coolant twice since I've owned the truck and I've always used Fleetguard Compleat. All the hoses and the thermostat were replaced less than 2 years ago. Any ideas?