Has anyone experimented with adding additional insulation under the Prius' hood? More specifically, has anyone installed any kind of Radiant Barrier Reflective Foil insulation (with the primary objective to speed up the warm up cycle and keep the gasoline engine warm during the winter ) underneath the Prius' car hood like the ones sold by koolmat[1] or Amazon[2] or Ebay[3]? [1] Motor Armor Foil Insulation [2] http://www.amazon.com/HEAT-SOUND-Shield-INSULATION-BLANKET/dp/B001AX87A6 [3] ARMA FOIL Radiant Barrier Reflective Insulation, 500sf | eBay
I have loosely wrapped the ICE with the foil backed insulation. It seems to help with warmup times and heat retention: http://priuschat.com/forums/gen-ii-prius-modifications/70513-ice-radiant-heat-reflector-gen-ii.html
The nice thing with the prius (gIII) is you wouldn't have to worry about as many moving parts (e.g. belts).
I did at one time, It may help the ICE stay a bit warmer during long glides and ICE off periods, but honestly since removing mine (it fell off where I had it stapled on the underside of the hood), I can't tell any measureable difference.