He sounds more knowledgeable than me, but there are a few things I have problems with in his arguement.
First, the suppliment is an additive to "reduce porisity". I'm assumeing from the text that it coats the aluminum and seals it. I would think this is a GM method of fixing one of the biggest screw ups in Caddilac history, and there have been some doosies in the last 25 years. The 41.-4.9L motors used a wet cylinder block that would leak THROUGH the block. Really hard to fix a leak that had no gasket. They also had a oil passage plug behind the cam gear that fell out and into the oil pan leaving you with no oil pressure, but that's another story. I'm sure, especially given the lack of customer service Caddy gives it's customers when they sell them a junk engine, (Cataras, 4.1-4.9L, 4-6-8 engine, diesels, etc.etc.) Caddilac had given them this "mechanic in a can" crap to try and keep the engine together until the car fell apart around it. It might work in a Cruiser, but if it did, I have to think it would be marketed to everybody and we would have heard about it.
Second, the guy goes on about how good Dex-Cool is. How it never needs replacing because of the corrosion inhibitors. Never does he mention the fact that they are seeing GM cars get gunked up radiators as early as 50,000 miles. There are a lot of GM dealers out there reccomending that you replace the Dex-Cool with Green stuff as the Dex Cool does not work as advertised.
He says that Dex Cool prolongs the life of water pumps due to the lack of silicate build up and abrasion on the seals. I just finished a 98 1500 series van that junked it's factory water pump inner seal at 30,000 miles. Could have been a bad part. Does nothing to convince me that Dex Cool is better, though.
I am not a fan of Dex Cool because I don't know that it works better based on anecdotal evedence, however it is important to keep in mind that the plural of anecdote is not data. It might be better. I just don't like something that makes my life as a wrench harder. Dex-Cool adds complexity to something that worked pretty well before.
I am not a fan of Cadillac, either. Can you tell?
GM has a long history of putting absolute junk out there for the consumer. In cadillac's case they have a terrible track record. Worse, they are ruthless about warranty limits. I have had to deal with way too many customers that bought junk based on the brand name when it was out of warranty and have been absolutly hosed. GM uses Caddy's name, price base and brand loyalty to test new technology. That's fine, but step up when it doesn't work and take care of the customer. All the customers, not just the blue hairs that trade their Eldos in every two years.
Besides, they are the ugliest cars I have ever seen. AMC thought they could screw up a car. They got nothing on Cadillac.
The thing I don't like about Green is when it sits in the overflow tank you get a green mud/clay like sludge on the bottom of the tank It can't be good for the rad or engine for that sludge build up. I don't know if you get sludge with the orange or red stuff. Maybe I should go Toyota Red