Need Opinions - Water Wetter vs. NPG+ - PeachParts Mercedes-Benz Forum

Phalcon51 · #1 07-17-2002, 12:45 PM

I've searched through the old posts and I've been to both company's website and read all the info. They both seem like good products. I think the NPG+ may have the edge in actually controlling localized engine heat, but it seems that it doesn't shed the heat as rapidly as a water-based coolant and consequently allows the engine to run hotter, which may allow for more efficient burning of the fuel-air mix.

What I'd like to know is whether anyone here has actually tried the NPG+ and what kind of average temp increase you experienced. I'm not worried so much about the engine running hotter, I think it can handle that just fine as long as there are not focal hot spots in the head. I'm concerned with whether or not the cooling system and climate control components will be overtaxed. Is it likely to trigger the aux. fan to come on constantly, or will it trigger the emergency cycling or shut-off of the A/C compressor starting at 120 C.

If the average increase is only a few degrees C, no problem. If it's closer to 8 or 10 degrees C, then I will reconsider.

Thanks for your help once again.

Gary

jsmith · #2 07-17-2002, 02:08 PM

you have to completely drain your water based coolant and replace with npg+. the aux fans trigger at 105C and the thermostat opens at 87C, those are what you probably need to adjust, mainly the thermostat although i think MB temps are already optimum ( i think they want you to modify your system to run hotter). the coolant won't boil off at all which can happen in water based systems. non-water based coolant ideas have been floating around for a long time. the problem is when you lose coolant you have to replace it with the same special liquid...

suginami · #3 07-17-2002, 02:36 PM

check out this thread, particularly the posting from tkamiya on page 1:

LOGIC REQUIRED -Engine Temp What Is Normal??????

This information came from 20-0020 "Switching points in cooling system"

"For W124s,
Thermostat will start opening at 85 to 89
Thermostat will fully open at 102
Viscous fan clutch will cut-in at 96 to 104
Viscous fan safety cut-off will ocurr at engine rpm 4500
The same will ocurr at fan rpm 3250
Electronic fan (1st stage) will cut in at 16 bars of refrigerant pressure)
Electronic fan (1st stage) will cut out at 11 bars
Electronic fan (2nd stage) will cut-in at 107
Electronic fan (2nd stage) will cut-out at 100
A/C will go into 50%on, 50%off cycle (20 seconds interval) at coolant temp 121 to 123
A/C will go into emergency shut-off mode at 126 to 128
Pressure cap will open at bar 1.3 to 1.5
Coolant temp max is 130"

Your thermostat starts opening at 85-89, but isn't even completely open until 102.

stephenson · #4 07-18-2002, 01:32 AM

51,

There are several posts on Water Wetter ... no one has been able to come up with independent testing to support their claim.

Some believe that WW appears to lower temps just a very tiny bit and it is likely associated with WW specifying a higher water to coolant ration, hence just a tiny bit more efficient at cooling - higher water content equals cooler temp, all other things being equal.

BTW, I lived in Florida - never did find the fountain of youth. Don't think there is magic in this line of effort, either.