I read somewhere that zerex G05 was the right stuff, but my local mechanic said you should not mix the two because they’re different colors? Who’s right? This is for a 2014 E350.

Blue or Yellow are both identical coolants.

I've mixed ethylene and propylene together and nothing happened. Those two are the only coolants I know of but maybe they've made a new one now?

someone else online said that g05 is for older benz models and that if my car has blue coolant I want g48? I’m confused.

someone else online said that g05 is for older benz models and that if my car has blue coolant I want g48? I’m confused.

Yes, don't mix colors is a good practice.

(just know that these really are the same. MB did not use Blue for very long before switching again for some reasons.... so I stick with G05 they had for the longest time!)

Either way, your cool8ng system is safe.
👍

So adding G05 to my MB blue coolant is safe? No need for G48? Just making sure I understood right. Thanks again

Use MB compliant fluids. Google operating fluids Mercedes.

You strike me like someone who likes to know, right?

-1. Yes, exactly 100%: G05<=>G48
Don't take my word, compare the specs.
[The one thing you NEVER want to use is TAP WATER because the electrolytes will eat holes in the radiator!]

-2. While you're there do a good job....
Renew the old coolant with a simple "drain & fill".
--> Cost you $20 + 30mn free time.


-3. The standard coolant leak is the 5¢ O-Ring seal for the hose to the expansion tank. Available at your favorite OEM parts distributor.

Then your cooling system will be trouble free - Enjoy!

To continue the coolant thread, I just dumped the coolant out of my recently purchased 08 ML320 CDI. It was straw colored, likely the original G05 that was used by MB up until about 2012 if my research is correct.
BEVO now advises to use G48. I read an MB document on this forum dated 2012 that advised the G05 was being replaced with G48 when sold from the parts department and no compatibility issues reported.
I have both G05 an G48 Zerex brand in my shop. Draining the ML produced about 7l of coolant, so approximately 2.5l remained in the system.
I was prepared to refill with G48 when I was sucked into the vortex of doubt......
I called the tech line at Valvoline and spoke to a tech (presumably, he seemed very knowledgeable discussing chemical compositions) and asked him if there were any "issues" refilling the system with G48 when some G05 remained in the system and he suggested that I use G05 unless I was prepared to flush out the system of the old G05 completely. He said there wouldn't be any issues but he never recommends mixing chemical compositions.
So I refilled it with fresh G05.....

And, yet Mercedes says use tap water. But I use the premixed 50/50, not concentrate. Of course, for all I know they use plain (unfiltered) tap water at the manufacturer.

And, yet Mercedes says use tap water. But I use the premixed 50/50, not concentrate. Of course, for all I know they use plain (unfiltered) tap water at the manufacturer.
Also, as for #3, the prior owner of my GL crazy glued the hose to the expansion tank nozzle (which looks like it was broken). I changed the expansion tank. Drive a lot in the desert and don't need that hose coming unglued.

Can you point to the official source from Mercedes that says that? I'm just curious since you never know how hard or soft the water might be and whether it is untreated from a well or fluoride-enhanced from a public water source.

Unfortunately, I cannot find the link. I believe it was on a specific dealership's website. However, I believe it was in the context of what to do if you get a low coolant warning and the idea was that 50/50 mix with tap water is better than 100% coolant. In any case, I would not be inclined to use San Diego tap water if other alternatives were available. But, that's why I use the prediluted coolants.