The water is what helps cool the engine , the antifreeze is for well so the water doesn't freeze and to lube and protect the internal parts from corroding due to there is water in the system....and also (I believe) to keep the boiling point of the water high (so it won't boil). If you put straight antifreeze into the engine....it won't cool it as efficiently (especially in this heat!) and may even come close to over heating. Follow the mixture. I believe Prestone makes ready mixed antifreeze so you don't have to go through the trouble. I would suggest that you fix that leak because it will turn into a major problem unexpectedly. Even though it is very small?.just from the heat of the coolant expanding and contracting the parts it will get worse. Steve --- In dmcnews@xxxx, Michael Pike <iqintermedia@xxxx> wrote: > Here is my question - antifreeze says 70/30 mix > maximum...> > Can I put straight antifreeze in the car?