I have a question regarding a particular brand of coolant used in MB's. Until now I have used distilled water until I change over to MB coolant. I've wondered why most techs I've talked to (in Georgia) have recommended PEAK antifreeze as the coolant they use if not MB brand. Two indies only use PEAK in the MB's they service ...Is there a specific reason for this? Of course I've flushed and filled my system with the PEAK pre-mixed formula (that states not to add water on the bottle) and bought like another four bottles for my other cars because they were clearing them out at Target for a buck each instead of the regular $5. My question (after the fact) to anyone in this forum is what kind of antifreeze do you use (if MB coolant is NOT used) ? Is PEAK's formula decent for the use in MB's? Just wondering.