You guys can do what you want, but I'm sticking with the Dex-cool. Like I said, thats what GM recommends. Its even in your manual. My old truck over heated when I used the neon green, and it was an 05' GMC 5.3

 

I flushed mine the day I brought it home, put green in it and have been givin it hell ever since!!!!! Green will not hurt anything, just dont mix them

 

i've seen the orange stuff gel up in a few motors. i say drain it and run water with a touch of coolant. weather it be orange or green. i don't. i run water with water wetter. but you don't have to be like me.

 

if prestone puts all makes all models, will mix with anything on the bottle and anything happens you can get a new engine.

 

Here's a link that may be a bit educational to readers. Here's another that might help. I was going to try explaining it all, but decided I might screw it up, so there ya go.

There are a few versions of coolant available these days. Your owners manual tells which your system should get. The 50-50 mixes available are just coolant and H2O and not worth the money imo. I don't know how many actual plants or companies physically make coolant, but I'd bet the number is quite low, even with the different types available.

For those who think green and orange are compatible, they really aren't because one will offset the value of the other when mixed in the same system. There are a couple which are different the the rest and at least one(dyed yellow) compatible with any typical version.

 

those are outdated, the new antifreeze is glycol free.
http://angryiron.com/Berserker90sml.jpg
this stuff has been on the market for less than a year.

 

so am i right in thinking that straight water will cool better than coolant? im in texas near the cost so dont really have to worry about freezing....

 

without the antifreeze your water would vaporize and come out as steam through your overflow. that would be kind of bad.

 

I run Evans NPG waterless coolant with a Evans waterpump and a custom double pass aluminum radiator.

 

NPG+?