First off, Dexcool is not crap. It's the typical old wives tale that gets told again and again until it becomes truth. GM has been using Dexcool exclusively in all of their product since 1996 (except for Saturn which began in 1997). That's 8 years and millions of vehicles. They must be real idiots over at GM.....
The real reason Dexcool got an undeserved bad rap is:
"There were some cases with the GM 4.3 V-6 engine, where the cooling systems would fail if the system was run low with DexCool. The uncovered iron surfaces in the engine (due to low coolant) would develop surface rust (corrosion protection is maintained only by direct contact with coolant) and then that rust would wash into the system as coolant sloshed around in the engine. As the DexCool built up red rust particulates it would foul the sealing surface of the radiator cap and cause it to unseat and exacerbate the low coolant condition with overheating due to loss of pressurization. Unfortunately, the coolant supplement GM added at the time to all production vehicles (used by GM for many years with green and Dexcool coolants) was viewed as detrimental to this particular failure mode as the fibers (that would normally seal a leak) would coagulate with the red rust particulates and make the cap seal unseat even worse. For this reason the coolant supplement / sealer was eliminated from production."
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DEX-COOL Extended Life Anti-Freeze/Coolant.
By Scott Mueller
"A revolutionary new type of long life engine coolant is now being used in all GM cars and trucks. It is called Dex-Cool, and can be distinguished by it's unique orange color. Dex-Cool is manufactured for GM by Texaco Havoline, and is rated to last 100,000 miles or 5 years, whichever comes first.
Dex-Cool is an Ethylene Glycol based high performance coolant that contains unique corrosion inhibitors, which are different from anything else on the market. Dex-Cool is vastly superior to conventional coolants, which use silicates, phosphates, borates, nitrites, nitrates, and amine additives to eliminate corrosion. These additives are abrasive to water pump seals, and silicates are especially unstable and drop out of solution and form a gel after time. All of these conventional inhibitors deplete after a short time, which is why conventional coolant must be changed every year.
The unique corrosion inhibitor technology in Dex-Cool is based on the use of two organic acids, which are synergistic and combine to form carboxylates. Texaco refers to this as Organic Acid Technology (OAT), or Carboxylate Technology. The corrosion inhibitors used in Dex-Cool deplete very slowly thus eliminating the need for traditional additives, or frequent change intervals.
Note that contrary to what some may say (or write), you can indeed mix Dex-Cool and conventional coolant with no ill effects. However, if there is more than 10% of conventional coolant in the system this will reduce the concentration of the Carboxylate such that conventional coolants change intervals must be followed. In other words, if you mix it, you can't leave it in for 100,000 miles or 6 years, but instead should treat a mix just like conventional coolant and change it every year until the concentration of Dex-Cool is over 90%."
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Am I saying that everyone should switch their Vipers to Dexcool? Absolutely not. I'd recommend staying with what the factory put in it. Warranty claims could be difficult otherwise. Do I use Dexcool? Yes. Have I had any problems? No. I've used it in a 1994 Ford Taurus, a 1970 Pontiac Trans Am and a 1994 Chrysler T&C, and ran about 50,000 miles with it on the Ford and Chrysler. All came with green from the factory. Results are perfect radiator cores, clean thermostats and housings and 100% corrosion free water pumps (observed while changing hoses). I drained the green from the system (including the block), refilled with distilled, ran until warm, cooled, drained and repeated. Poured in straight Dexcool to 50% of capacity and topped off with distilled.
Lastly, I've read SAE white papers on Dexcool, where taxi cabs were run with 50/50 mixes of Dexcool and green with no adverse affects.
Better than green? Better than Chrysler orange? Worth the effort to swap? Your call.....
