I had an e-mail exchange with the tech folks at Valvoline that I thought some of you might be interested in reading. The Zerex G-05 and the Mercedes coolant apparently are not identical, but probably close enough for government work.
ME: Is Zerex G-05 identical to the Mercedes branded coolant that I would buy at a dealership? Also, since it seems like AutoZone no longer carries Zerex G-05, where can I find it in my area?
ZEREX: Yes, the Zerex G-05 is the approved coolant for the Mercedez Benz application. Our biggest supplier for the product is Carquest Auto Parts. Other options include Napa, Auto Zone, Advance, O'Reilly's, & Pep Boys. If these places don't carry the product, please just ask them to order it for you.
ME: Thank you for your reply. Is the Zerex G-05 identical to the Mercedes branded coolant? Earlier this year there was a rebate on the purchase of the Zerex G-05. Are there any plans for a repeat of that promotion in the works?
ZEREX: It is not IDENTICAL, but the Mercedez formulation and Zerex G-05 are 100% compatible. I am not sure about promotions. Please give our hotline a call at 1-800 TEAM VAL and ask for promotions for this information.