kung gagamit ka na rin lang ng 100% distilled water, might as well use a coolant/distilled water mix (30/70 to 50/50 mixture will be fine for our winterless climate). hindi naman mahal yung coolant, at wag kang maniwala sa mga nagsasabing nakasisira ng makina o radiator yung coolant. remember, water is corrosive to aluminum, which is what radiators are made of.

actually, distilled water talaga dapat ipanghalo mo dun sa coolant. don't use tap water (maraming dissolved ions yun na babara sa radiator mo). one-time expense lang naman yan.

jtdc,

i don't think using 100% coolant will cause the engine to take a longer time reaching operating temperature. pure ethylene glycol has a higher boiling point, but that won't mean the engine will take longer to reach the proper temperature (since the operating temp of the engine isn't dictated by the boiling point of the coolant; the engine doesn't reach proper operating temp by boiling the coolant).

pure antifreeze is not recommended mainly because it has a higher freezing point than an aqueous solution (in fact, the lowest freezing point is achieved with a ~70%/30% mixture), among other reasons.