Someone mentioned Water Wetter (Scott? maybe) as cooling aid.  It actually
does work.  I used it in my racecars and saw about 10% temperature
reduction.  As I recall, it is said to be compatible with all anti-freeze
compounds, which I never tested...racecars must run plain water as coolant..
  Side story: Off topic

  My Porsche 928, back when I had some disposable income and raced,  needed
body modifications for bigger tires (I ran 12.5 x 17 Goodyear race slicks)
so I had a body shop add 5-6" into the front fenders.   When they put the
nose back together, they didn't get all the A.B.S. internal air baffles
clipped back into their retainer clips quite properly.  This caused
mysterious overheating.  We tried everything looking to cool down the motor
on sustained high speed runs...It would only overheat if you got up over
about 150 and held that speed..

  We finally found the problem while working on something else.  They left
out the clips that held the air baffles under the radiator and out to the
nose..So, when stopped or just going slowly, they laid in there just
fine...but when you went fast, they blew out of position, into a vertical
alignment across the bottom of the radiator!..Slow down, and they returned
to proper position...

  That was when I became familiar with Water Wetter, trying everything to
keep the Gnarly 928 in a reasonable temperature range.

  Don Hanson