So I've been using Zerex G05 for years because when I got my truck I was told that's the factory (same as motorcraft gold) coolant and it was the same price. I needed some the other day and now its up to $20 a bottle whereas universal green is like $10 so I was thinking about changing it. Do you think I can mix the green right in with the zerex or should I do a flush? Or should I tough it out with the yellow stuff, whats even different about it?

 

G05

 

Okay so here is the real issue I see. You have what is known as a hybrid coolant (no this does not mean its for hybrid cars, its a mix of two different styles of coolant)It is a mix of organic acid and silicates. The base is the exact same as the green but it has a mix of organic compounds as well that make it a better fluid (better is subjective just saying). The devil is in the details. You can absolutely change it but I would flush the absolute crap out of it and up your coolant change frequency just a pinch. Green ethyl glycol coolant doesn't have nearly as long of a life span but works all the same.

This is Zerex G-05 the 2 extras you see are apart of the extras that make this a hybrid coolant.

This is Peak "European" (litterally means nothing js) this is just green coolant with a bittering agent labeled on it instead of generically marked on the Zerex lol.


The issue I was referring too is that the organic phosphates don't like mixing with the silicate. The green stuff is much more heavily silicate based, what happens is the organic compounds solidify and mix turning into a gooey bubblegum of sorts. On the Hybrid coolants its not super severe. "HOAT" like Zerex G05 claim to be phosphate free, don't think id trust that though. You could readily mix any silicate coolant and be fine for thousands of miles. Wouldn't go past a few oil changes but you get the point. Its not apocalypse bad or some weird scientific experiment gone wrong. Just not a good long term.

If you want to switch flush thoroughly. Chris fix flush it till water comes out clear 3 times. SERIOUSLY FLUSH it out. Then make the switch to green. I wouldn't worry about "degrading the seals blah blah" just be sure it doesn't mix and you should be fine. People switch over GM Dexcool engines because they hate the organic acid coolant with a passion quite litterally all the time. Super common. Many vehicles like that even say goofy things in the manuals. I had an 08 forenza that claimed it used both in the manual, but to use whatever the factory had used. That said, I am a firm believer if its what's in the car its probably best you keep using it. How often are you changing it out that you're worried about the difference of $20-30 bucks ya know?

Just my opinion, do your own research