Typical answer from a snake oil...I mean amsoil dealer.Hate Dexcool because it gums up the tank cap and thermostats. I use the Amsoil coolant in Class 8 trucks its warrantied for 750,000 miles its good enough for mine. Its concentrated so when you buy 1 gal it makes 2. Your 2005 has a drain on the bottom of the radiator. Its on the passenger side on the engine compartment side of the Rad. Drain it fill it with water run and drain again. Then fill with your choice of fluid knowing that there is about a gallon or more left in the block. :thumb
Correct!Dex, that's what the truck was designed for. If you do decide to switch brands, make absolutely sure you flush every trace of Dex out before you refill. Some brands will coagulate when mixed with even a small amount of Dex, that's what causes problems. My truck is 10 years old, never had anything but Dex in it and cooling system and tank are clean as new.