Michael Tucker

i want to use royal purple but i dont want to use the hard tap water. is it better to use distilled water?
thanks,
Mike

GaryS

Equal parts of distilled water and your favorite antifreeze. I like Preston(greeb stuff) for our older cars and the Havoline Extended Life(orange stuff) for my newer cars.
Gary

81vette

Fill it up with distilled water first, and check for leaks etc. That way if there is a problem you don't have to worry about dumping the royal purple or recycling. If everything checks then re-fill 50/50.

mark

914eener

Even though the radiator is aluminum you definately want to use distilled water. It's available at any major grocery chain for about a buck a gallon. To make a 50/50 mix with the green stuff it will take a little less than 2 gallons fo the initial fill.

Are you also changing the water pump for a high flow unit? I used the Stewart stage II when I installed the same radiator and love it.

zwede

Filled mine with 50/50 of tap water and dex-cool. That was 3 years ago and it still looks new. No sludge, rust scales or other nastiness.

norvalwilhelm

I'm also a fan of Dex Cool The first year I had my new aluminum rad I filled it with a 50/50 mix of prestone, the green stuff and after a year the inside of my new aluminum rad had a white deposit all over the inside. I switched to dex cool and the film disappeared and the inside looks totally clean.

SmokedTires

I went 50/50 with distilled & antifreeze in mine without any cooling problems so far :) .