AlTrudell

Have a 2013 (gas) GLK 350. What is the recommend engine coolant/antifreeze as well as the correct mixing ratio. MB manual is confusing. Have a Pep Boys right down the street. Thanks

mjhawkins2346

I read an OP that suggested in a post that Mercedes uses Zerex Z03 (from memory). You might want to search the forums for coolant to confirm this.

mjhawkins2346

It is Zerex G05 per another post here on the forum. Pep Boys has it too, apparently.

ddombrowski

Yes, its Zerex G05, however, coolant change interval is around 150k miles. Coolant is easy enough to change that I'd consider doing a halfway (more like 2/3) change at 75k and then another halfway change at 150k

Pep boys carries the G05, AAP and Autozone do not.

I've heard rumors that carquest/bumper-to-bumper carries it as well.

Mixing ratio is 50/50. I'd make sure to use distilled water.

Don't feel like you need to change the coolant out 'just because'. When I drained coolant on a '10 with 85k miles there was no scale, sludge, or deposits that I could see. My opinion is that most of that stuff comes from using tap water, or a combination of tap water and the protection package in the coolant wearing out.

fabbrisd1

Well kindof yes and kindof no - Zerox G05 is 100% compatible with Mercedes coolant - but for the MB Coolant is a bit chemically different.

A MB dealer "should" prvide free coolant top-off - and coolant change to fresh is normally recommend at 100K - when using MB coolant/concnetrate the proper mix is 50/50 with distilled water only.

pH of the coolant needs to stay neutral as not to start internal electrolytic reactions inside the multi-metal engine components - is some non-North American lkocales such as the Middle East and Australia - the use of alkali-trend tap water fracks things up a lot..

PHML

The stuff in there now is the blue MB coolant....can I top off with Zerex G05 and mix it with the blue stuff?

NYCGLK

Good to know. I saw your DYI and was going to do this. But it seems unnecessary. I read there is a cartridge that releases additives over time, hence such long service time, but at the same time I don't think MB cares what happens to the car after 6-7 years.

jonUF02

I'm wondering the same thing. I have some of the G05 at home that I used in my old CLK, but my new E550 is giving me coolant warning every morning. It has the blue stuff, It's only maybe an inch low in the reservoir when cold in the morning, and seems full when warmed up.