coolant mixture ratio

tmar04 · Dec 31, 2007

If the ideal mixture ratio is 70/30 antifreeze, what is the freezing temp limit on this mixture? How in the world do people in the extreme north get by with this ratio? Also, why does this mixture work better in Yanmar tractors, when the industry standard is pretty much 50/50. thanks to all.

Doc_Bob · Dec 31, 2007

I use 50/50.
Bob

easygo · Dec 31, 2007

Around here it gets as low as 25-30F below zero at times. My dealer said to use 50/50 or else...

MikePA · Dec 31, 2007

tmar04 said:
If the ideal mixture ratio is 70/30 antifreeze, what is the freezing temp limit on this mixture?

Who said 70/30 is the ideal mixture?

From Filter Council

Q: What is the correct water and antifreeze mixture to be used in coolant systems?

A: The ideal mixture is 50% water and 50% antifreeze. The coolant mixture should never contain less than 40% antifreeze or more than 60% antifreeze. The water used must meet engine manufacturer's guidelines for use in their coolant systems.

From Universal Environmental Services, LLC,

What happens if I use too much antifreeze or water?

Using too much antifreeze or water in your engine coolant can harm your vehicle. Antifreeze concentrations higher than recommended levels can cause problems including corrosion, water pump failure, and increased engine wear. Increasing the concentration of ethylene glycol above 60% actually hurts the engine’s freezing and overheating protection. More is not always better!

Adding too much water to the cooling system lowers the concentration of corrosion inhibitor and antifreeze and results in decreased protection against corrosion and freezing.

RalphVa · Jan 1, 2008

All recommendations I've ever seen have been to use 50/50.

If you're in an area where it gets down to around -40 F/C, maybe you need to use 70/30. However, I think 50/50 protects down to this level. Think it's good down to about -70 at 70/30. Search for info on ethylene glycol. I've seen a site somewhere that gives the plot of freeze point vs. % ethylene glycol. Think the eutectic (minimum freezing temp) is about 70/30. Vaguely remember that it's about -70 F.

Think you'll find the freeze point of 100/0 is 4 F! Freeze point of 0/100 is 32 F.

Ralph

MikePA · Jan 1, 2008

Even though it's already been posted that 70% is not recommended along with the reasons why.

daTeacha · Jan 1, 2008

Not wanting to spoil a good discussion, but most anti-freeze bottles give the temperature range, both freezing and boiling points, for various dilutions of that particular product.

Just be sure to get an antifreeze that is compatible with your engine components and the antifreeze you already have in there. They are not universally interchangeable nor universally mixable. Read the labels.

Also, the corrosion inhibiting properties can go away with time (at least that's what I've read), hence the need to replace the coolant periodically. Just testing for freezing point does not mean the stuff is still good.

joe48 · Jan 1, 2008

daTeacha said:
Not wanting to spoil a good discussion, but most anti-freeze bottles give the temperature range, both freezing and boiling points, for various dilutions of that particular product.

A) this is usually true and the best place for info on the particluar product.

Q) Just be sure to get an antifreeze that is compatible with your engine components and the antifreeze you already have in there. They are not universally interchangeable nor universally mixable. Read the labels.

B) actually most automotive AF's are brand interchangeable and mixable , again check mfg. instructions on bottle. In automotive normally you can't mix etylne and propylene, in HVAC work they can be mixed althuogh rarely done. That's from the recommendations of several mfg's that I sell bulk AF for HVAC applications. (15,000 gals last year)

Q) Also, the corrosion inhibiting properties can go away with time (at least that's what I've read), hence the need to replace the coolant periodically. Just testing for freezing point does not mean the stuff is still good.

C) This is correct the glycol does slowly decompose into glycolic acid , which then lowers pH and causes corrosion and consumes the additves. If the Ph and % glycol are monitored and kept up by adding glycol or corrosion additves the glycol can last almost indefinitly, at least in HVAC situations.
In automotive applications it's just cheaper and easier to change the AF every 3-4 yrs. Also a side note; most auto applications still use ethylene which is poisonous , HVAC almost exclusively uses propylene because it is NOT poison and is environmentally friendly. Propylene is used in many food products, just without any additives.

Soundguy · Jan 3, 2008

tmar04 said:
If the ideal mixture ratio is 70/30 antifreeze, what is the freezing temp limit on this mixture? How in the world do people in the extreme north get by with this ratio? Also, why does this mixture work better in Yanmar tractors, when the industry standard is pretty much 50/50. thanks to all.

I see nobody bothered to comment on the yanmar part of your question.

Most of the grey yanmar under the 2000 model don't have water pumps.. and thus are thermosyphon engines.. high a/f freeze mix ratios can effect water density and flow.. I think that's why meny peopl euse a lower than ideal mix..

soundguy