I've never experienced any sludging with Dexcool and I've been using it in all my cars since '95, but am in the process of switching all but the MR2 to G-05.

GM claims in several TSBs that sludging and corrosion is the result of running with low coolant over extended time/mileage intervals. Apparently some of the components in Dexcool can oxidize if there is a lot of air in the system.

My opinion is that these Dexcool lawsuits have little merit.

Duke