passive101

I have a 2004 Civic. The temp is going to be -40F tomorrow. I'm currently running 50/50 Prestone mix. Should I risk it?
Also for in the future to not have to worry about this, can I just run straight 100% antifreeze or do a higher 60-70% mix? Is there any downsides to doing this at all (other then a slightly higher cost of coolant)? The cost of coolant doesn't bother me to not have to worry about this problem.

2nd question. What type of coolant does the 2004 Civic use? Green, orange, or something else that honda likes?

Colin42

Is that with the windchill?
You should be fine, we had a day like that in my area last Monday and my car had no problems. How old is your coolant?

passive101

I'm not sure how old the coolant is in it now. It's -28 without the wind chill currently. It did have 50/50 put in it a few years ago I think. That's what most people use around here.

Colin42

You can by test strips or a hydrometer to test the freeze resistance of the coolant, any parts store should have them

BrotatoChip

Neither water or antifreeze are perfect by themselves. Straight water causes corrosion, straight antifreeze doesn't cool as well as water. Here is a chart showing freezing point of antifreeze/water mix found by a quick Google search. 50/50 mix should be good down to -38C, 100% antifreeze will freeze at -12C.

mikey1

100% antifreeze is worse then 50/50 mix

why not just make it easy and use honda premixed antifreeze?

passive101

I don't have a problem making the mixes. I just don't know what the mix should be that would be ideal. Is the honda pre mix any different then the regular antifreeze mixes?

ezone

Is that 50/50 premixed, or was it straight antifreeze that you mixed with water yourself?

On the back of every undiluted antifreeze gallon jug is a chart that tells the freeze protection for various mix ratios (so the installer can mix to their needs)



If prestone has been ok for you, keep it.

Straight 100% antifreeze is not good. Lousy heat transfer and straight antifreeze can slush or freeze before a mixture does.


Wind chill is not relevant. Machines are never affected by wind chill.

passive101

That's good to know. I didn't mix what's in it now .I recently got the car and was lazy on that part. I wasn't thinking it would get that cold. It usually doesn't.

ezone

Have you actually checked the freeze protection of what's in it now?


Warning: some time back I picked up a low cost tester at walmart and it was absolutely WRONG.
IIRC it was a well known brand name
Beware.

passive101

I don't have a tester but it worked down to those temps. The previous owner told me it was 50/50 though.

Does this car take the green or orange type?

ezone

Hondas Type2 is blue (and 50/50 premixed), but that's not the only factor. There are many colors and many types on the market, and color is not always an indicator of a specific type.

Type2 is Ethylene Glycol, silicate free and borate free

passive101

I only see green and orange usually. Is the Honda one better? And is it made for a 2004 that makes it better then the standard 50/50 mix for my car?

ezone

IMHO a thing that makes hondas coolant "better" is that it's absolutely right for the car, no question.
There are other brands that offer many modern technology coolants as well and have products that meet Hondas needs, but you may have to do some hunting and reading


It's my understanding that Hondas water pump seals are not designed to be used with coolants containing silicates.
My personal observation has been that ever since type2 became the factory fill coolant around 2003-2004, water pump leak problems were greatly reduced overall.
If you need a mix stronger than 50/50 a Honda dealer should be able to get small bottles of straight type2 so you can increase the freeze protection level without resorting to aftermarket products.

But again if the prestone has been ok for you I would probably keep it. Easy to find, reasonable prices,and you can mix it to whatever ratio you want.
Couple possible caveats I thought of: Local tap water quality can be an issue when you have to mix it yourself, and suggested coolant service intervals for most ordinary coolants are like every 2 years.

passive101

Does the Honda stuff last significantly longer? I used distilled water.

ezone

Look at the maintenance schedule in your owners manual !