A 2005 Chevy Trailblazer requires a
Dex-Cool type antifreeze/coolant.
Do not use traditional green antifreeze (ethylene glycol based) as it's incompatible with the Dex-Cool (OAT - Organic Acid Technology) system and can cause serious damage.
Make sure to check your owner's manual to confirm this, but Dex-Cool is the overwhelmingly likely recommendation for that year and model. If you're unsure, using a Dex-Cool compatible antifreeze is the safest bet.
