running water instead of antifreeze

Let's get it straight without insult.

Water has a higher heat capacity (the ability to absorb and tranfer heat) than either ethylene or propylene gylcol. Thus mixtures of coolant and water have lower heat capacity than straight water.

Water has a higher freezing point than either ethylene or propylene gylcol. Thus mixtures of coolant have a lower freezing point than straight water.

Water has lower boiling point than either ethylene or propylene gylcol. Thus coolant mixtures have a higher boiling point than straight water.

Coolant mixtures sacrifice heat transfer ability for better freeze AND boil over protection. The lower heat transfer ability of coolant mixtures is compensated for by use of larger capacity radiators.

Straight water is OK in mild climate areas, but these same areas are the ones were boil over is a problem. So, In addition to the corrosion protection, coolant mixtures are generally better for all climates and situations.
 
Well I personall know redline watter wetter did not lower my operating temps when added to pure water. I am currently running GM's Red coolant because of alum. rad. and intake. I have tried it both with and w/o and saw no difference. I currrently run 40% antifreeze and 16psi cap in so cal. it gets hot but doesn't boil.

Oh and runnign distilled water is ok, but offers no electrolsis protection.

Never run deionized water it is a base and will eat your engine from the inside out.
 
Suprised no one mentioned this as a negative of antifreeze, but it will ruin your bearings in the motor if you blow a gasket and it reaches the oil.

I also use just water and anti corrosive. works fine as long as your not going to be freezing up. As for lubricating a waterpump, I really dont think that is necessary. I work on all sorts of pumps (commercial) with just straight water. The seals themselves are lubricated with the water itself and last a very very long time. Its when they run dry is when you damage them. Thats not saying antifreeze may not lengthen the life of it, but I'd think the bearings would go out first. :)