The good old radiator

It's a denial thing. I did it for many years. Tried this, did that. No matter what I did it didn't make a d@@m bit of difference. When I decided to pull mine I took it to a shop that rebuilt truck radiators. First thing the guy pointed out that the fins had broken away from the tubes. The second thing he commented on was it looked like a car radiator sized up to fit in the motorhome. I had 3/8" tubes and a 4 row radiator. They kept it 4 row but sized up the tubes to 5/8". The inside was totally coated in white. He told me to use any radiator fluid except the stuff that starts with a P. He said it seems like the heavily coated one used that stuff. It was the best $500 bucks I spent. Now with the 180* stat that's where it runs. I had this done about 6 years ago.