I tried Prolong just for the heck of it. Here is my experience.
327, mild cam, Electric Fan using Modil 1 synthetic will the Prolong. Usually runs at 200 degrees.
I was driving to a friends house and a short while before getting to his house (less than 1/4 mile) I floored it for a few seconds then let off. Little did I know, I threw a belt. I parked at his house and went inside. 4 or 5 hours later when I left, the car was stone cold. It was close to 12am. I live near the beach in Southern California, so the outside temp was in the 50's.
I left the house and I checked my auto meter gauges (that night it saved me). Water temp was stone cold and I had good oil pressure. I drove down the street and I saw the temp needle rising, fast. I was a little confused. The temp hit 120, 140, 160, 180, 200. And I was just down the street. My electric turns on at 170 and I still had oil pressure. I was confused. few seconds later I was at 220, then 240. I pulled over and shut it off imediately after seeing 240. I was still just down the street. I have never seen the temp rise so fast.
I looked under my hood, it was dark. I couldn't see anything. No leaks, I had oil. So what gives? Called my friend and asked if I could stay there until morning, then I could figure out what happend. I couldn't see that the belt was gone, too dark. So I left the hood cracked open, turned the heater and the electric fan on and went back to his house.
Then next morning I saw that I lost the belt. So the water pump wasn't spinning. So much for Prolong.
In the infomercial they drove a Viper on a race track in the desert. NO OIL, NO COOLANT. Well I had Synthetic oil, an electric fan and it was 50 degrees outside at the beach. SO what gives?
I wrote to Prolong, soon after this experience. I got no response.
If this stuff really worked you would hear it from a lot more people than just Unser and Yunick. Everyone would be talking about it and everyone would use it.
[This message has been edited by David Nafarrete (edited 07-03-99).]