Several ads in the flyers recently regarding anti freeze that is compatible with all types . Be careful of these they may cause problems in time. Do not mix types of anti freeze it may cause a jelling problem or increase the incidence of rust and or parasitic voltage. Check your owner’s manual and use only the type of AF that it calls for. Also keep a close watch on GM lifetime it can breakdown sooner than advertised. Check the Parasitic voltage in your AF you will be surprised at how much voltage is present in the coolant no wonder it attracts rust and other gunk. To check it either use a lab scope or a good voltmeter simply go from the AF to a good ground. Record this reading and check it periodically to see if it is increasing if so flush and fill time. The only exception is the environmental friendly type this as far as I have seen does not cause any problems still don’t mix only use for a complete refill. Check your owner’s manual and use the type it calls for also do the same with all fluids mainly transmission and power steering. Be extra cautious with the newer Chrysler type 3 and 4 many shops are saying the addition of a friction modifier will work but this is not the case use only the type called for by your owners manual.