Radiator fluid change?

[stirfry]

[:I]I've got 12,500 miles on my 2002 PT non turbo. I read it's a closed system, which sounds like better technoligy, little more complicated to change. I looked in the book, it says you should change fluid after 2 years, in one place but I also learned the Radiator fluid is good for like 100,000 miles. I guss it's the orange stuff. What is required to keep the warentee good. What is good rule of thum? [8D]

[quicksilverdon]

Unless you develop an overheating problem of some sort, it's my opinion that changing the mix often does more harm than good. Water is half the mix, and the water in your system now has been thru enough heat/cool cycles that all the air dissolved in it has been driven out. Air in fresh water can cause oxidation of metal. Also, depending on the water where you live, you introduce mineral that can cause scale when you add water. IF you want to be fanatic, consider distilled water for the mix.
Change the oil and transmission fluid, and leave the radiator alone.
My $.02.

[Sci-Fi]

Actually the service manual does mention using distilled water (see below):

From the Service Manual:

COOLANT

DESCRIPTION

CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection. Do not
mix coolant types. If coolant other than Mopar®
Antifreeze/Coolant, 5 Year/100,000 Mile Formula or
equivalent is added, the mixed coolant will have a
reduced service schedule.

The use of aluminum cylinder heads, and water
pumps requires special corrosion protection. Mopar®
Antifreeze/Coolant, 5 Year/100,000 Mile Formula or
equivalent ethylene glycol based coolant with corrosion
inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37°C (-35°F). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solution.
Mixing of coolants other than specified (non-
HOAT), will reduce the 5 year/100,000 mile corrosion
protection.