That was on my grand prix. The regal has 291K on the body but around 30-45K on the engine/trans. I wanted to flush the cooler because of the age. I think my problem might be the SD headers though. I noticed that with my slp headers the IAT was always around 10-15* more than the outside air temp. With the SDs its around 30-40* more. I did have a bit of a temp scare when i drove to west dundee Illinois. The trans temp on the highway was around 210* towards the finish of my journey.