I use RedLine's Water Wetter and Total Fuel System Treatment in both Benzes. I'll admit I can't say I see cooler temperature readings but I believe it does help.
With the fuel treatment I can attest to a 10% increase in fuel mileage. Great stuff.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.