I'm just a member like you all seeking new information. I only found out about this stuff due to "Running Too Hot" having posted the link.

However, as I understand it, depending upon your Mercedes, the pressure cap should only be rated for 10-12 PSI anyway. The radiator cap maintains the pressure in the cooling system, and in most cars, that's usually about 14 to 16 pounds, which is intended to raise the boiling point of the coolant mixture. As Evans already has a higher boiling point of 370-375°F, this added pressure is totally unneccesary...

Changing the pressure cap is both a longevity and a safety issue. First, you don't need the additional pressure to reduce the boiling point further. So, having a lower pressure system will increase the longevity of the hoses, as well as prevent a high pressure coolant release that could cause injury. And, keeping the system totally closed will prevent any coolant loss, as well as the introduction of any contaminants. Also, since the coolant is hydrostatic (it absorbs water), it is best to keep the system totally closed to avoid having it do so, as water is a corrosive impurity in this system.

BTW, Evans also eliminates the need for using Redline's Water Wetter, as it already serves the function better by totally eliminating all of the problems that WW is designed to overcome.

And, when you switch over to Evans, a sticker for the engine compartment is provided to advise any service technicians that this is a closed system consisting of a non-aqueous coolant. And that under no circumstances is anyone to add water or conventional antifreeze to the cooling system.

I will call Evans again tomorrow, and see if I can get one of their reps to check my answers for accuracy, or to answer these questions for you directly.

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."