I disagree.... in my IROC I lived in Florida and was told, "you can just run straight water down here, hiyuk! hiyuk! hiyuk!" Well - fine and dandy, but one of the major things antifreeze does is protect against rust and corrosion. within 6 months I was replacing a radiator and water pump because the water had rusted the water pump, and a chunk broke off and got lodged in the radiator. spend the extra 3 bux and get the antifreeze... it will save you in the long run. mike --- Mike Griese <mike.griese@xxxx> wrote: > The car will run hotter because antifreeze is not as > efficient at removing heat from the engine and > giving > it up at the radiator. You really should drain the > system and refill it with the proper mixture. > > For maximum heat transfer, you should use straight > water with some water wetter.