The temperature usually ranges from 1-15 degrees Celcius in the spring so I'm wondering if I should even add distilled water with my new coolant?

 

Plain water will be fine to 0, but if it freezes you're possibly screwed. Check the bottle, it probably has a guide on it for mix ratios and the associated freezing point on it. 50/50's probably a good ratio to run.

 

You can always get a coolant mix gauge, that shows what temperature your mix is good for. That's what I do. Even when I had my mix for -35 I still had water in it. Water cools, antifreeze is antifreeze and anti-corrosion. I wouldn't run just straight antifreeze in a street car in Canada.

 

Use the stuff that is already a 50/50 Mix..It is ScrewProof!

 

50/50 is perfect water is needed

 

agreed. always go 50/50... even in the shittiest winter that i've ever lived through i kept 50/50 and it was fine.

100% pure coolant will corrode the parts that it flows through.

 

Follow the instructions in the FSM/Owners Manual/Haynes. If I remember correctly, the spec is 50/50 which is what I run year around. 70/30 is also fine.

 

i live just down the valley from you and run 50/50 year round, no problems