Whats the best DEX-COOL antifreeze? 2002 Chevy Impala LS 3.8L?

Look in your overflow bottle and see what color the coolant is. You don't want to mix colors as the coolant will react and coagulate and create a serious issue. I believe yours will be orange or yellow. You can go to your parts store and get it or go to the dealer. It's twice as much from the dealer but you DON'T want to put in the wrong stuff.

It is true that dex-cool is not ideal, but Chevy says that is only if you mix coolants. My advice is to get your antifreeze from a chevy dealer if you must keep the car, but ideally unless you have owned the car from the start and know that it has only had dex-cool in it...get rid of the car and stay away from 96 and up Chevy until Chevrolet can admit to and come up with a fix for the problems caused by their coolant. This is from a life long chevy faithful...till now.