You will need an anti-freeze tester to provides a quick and accurate means
for checking the freeze point of SIERRA or any other propylene glycol based
antifreeze/coolant. There are two types of anti-freeze. 1. ethylene glycol,
2 propylene glycol. You simply observe the number of floating balls to
measure the degree of protection. They cost any where from $2.00 to $15.00.
You may also be able to buy anti-freeze test strips.

I prefer to use SIERRA Antifreeze. It is formulated with propylene glycol
(PG). As compared to ethylene glycol, propylene glycol is less toxic and
safer for children, pets, and wildlife in the environment.

SIERRA Antifreeze offers excellent protection for car and truck engines
against corrosion, freezing, and overheating. A 50/50 blend of SIERRA
Antifreeze and water has a freezing point of -26°F. If lower temperature
protection is required, it can readily be attained by increasing the
concentration of SIERRA Antifreeze - for example; a 60/40 blend of SIERRA
Antifreeze and water gives antifreeze protection to -54°F.

Please remember to protect the environment, anti-freeze is highly toxic to
animals and humans. Please take it to a facility that can dispose of it
properly. DO NOT JUST DUMP IT ON THE GROUND.

Jack
"Eric G." wrote in message
news
For many years I have winterized my boat systems using -25 degree RV
antifreeze. For some odd reason I can find only -50 degree antifreeze
this year. I don't need the extra protection (or expense since I use
20 gallons of antifreeze) since my boat is moored in a location with a
moderate climate. Is it safe to dilute the -50 degree antifreeze with
about 1/2 water to get me to approximately -25 degree burst
protection? Thanks for any input.