Straight antifreeze better than the dilute form?

How many of us have heard the story about "straight" (i.e., undiluted) ethylene-glycol antifreeze being just as effective protection against winter freezeover than the preferred 50:50 dilute form thereof -- only to realise the inevitable when an exceptionally cold winter's morning comes around and the car can't quite start?

[jumbofrank]

Wow. 4 years without a single reply. I think anything more than 70% is less effective. I remember a chart on the bottle years ago that had the temperature it was protected to at various concentrations. That was the old style antifreeze and the new type may be different.

[snakeseare]

Straight antifreeze actually freezes at a higher temperature than 50/50 mix. The minimum freeze temperature is at about that 70% mix you mention.

NOTE: Antifreeze also contains corrosion inhibitors. NEVER use plain water, even if you don't expect freezing temperatures. Your engine will rust inside, which will destroy the water pump and various other things.

[RichardM]

The answer to the original post is found on the container for the antifreeze. There is a table that gives you the proper mixes for the expected temperatures.

And for those that are required to run with no anti-freeze (like at a race track) there is a product called Water Wetter that works great. For others such as Jeepers, there are anti-freezes that are ecologically safe. These will not poison pets as regular anti-freeze will.

[BoKu]

Originally Posted by RichardM

...And for those that are required to run with no anti-freeze (like at a race track) there is a product called Water Wetter that works great...

Although, in some racing series even that is prohibited. When the rules say to run straight water, it's best to run straight water. It's not like that motor is going another 100K miles, or even 25K miles, anyhow.

[Alchemy]

Originally Posted by BoKu

Although, in some racing series even that is prohibited. When the rules say to run straight water, it's best to run straight water. It's not like that motor is going another 100K miles, or even 25K miles, anyhow.

Also important to note that absent corrosion and freezing/boiling issues, the best mixture of water and ethylene glycol or propylene glycol is 100% water. Adding glycol increases viscosity and reduces heat capacity, substantially so past 50-60% glycol. The addition of glycol (absent additional corrosion/microbial/etc. additives) trades the cooling effectiveness of the fluid for wider operating temperature.

[Not_Done_Living]

kind of an odd question bu t--

if Antifreeze is required to be mixed -- why don't the manufacturers mix it? wouldnt that make it more lucritive for them

[overyonder]

Originally Posted by Not_Done_Living

kind of an odd question bu t--

if Antifreeze is required to be mixed -- why don't the manufacturers mix it? wouldnt that make it more lucritive for them

They often do now.

The thing is that depending where you live (and possibly what car you drive), you may need a different dilution level.

OY

[Richard W]

If you add a little water to your antifreeze, it can help to bring out the top notes. If you prefer the earthier flavours, then I'd drink it neat, personally.

("Blimey, Iludium Phosdex is back," I thought when I saw this thread. But the OP is nearly five years old...)

[Spam & Cookies-mmm]

Originally Posted by Richard W

("Blimey, Iludium Phosdex is back," I thought when I saw this thread. But the OP is nearly five years old...)

Me too. Kind of disappointed now.

[Troberg]

Originally Posted by Iludium Phosdex

How many of us have heard the story about "straight" (i.e., undiluted) ethylene-glycol antifreeze being just as effective protection against winter freezeover than the preferred 50:50 dilute form thereof -- only to realise the inevitable when an exceptionally cold winter's morning comes around and the car can't quite start?

I've yet to see an engine which doesn't start due to freezing cooling liquid. The frost plug (don't know the proper English term) may have popped, and the engine will not cool as it should, but, if it's that cold, it's safe enough to drive it, at least short distances.

Also, as long as you have some antifreeze, it doesn't freeze solid, it just becomes ice slurry, which is less likely to damage the engine.

Whoa, y'all

Straight ethylene glycol (straight from the bottle, not diluted) does a great job of preventing corrosion and freezing. Straight water is the best at cooling.

The reasons for mixing water and ethylene glycol are pretty simple. Let's say you live in the south where temperatures never get below 25F and in the summer it frequently gets above 100F. In those climates you want less green stuff and more water, because you don't need as much anti-freezing, but the additional water helps transfer heat in the summer.

Let's say you live in Alaska where the temperatures rarely get above 80F and frequently get down to -30F. In that climate you need almost no water and almost all anti-freeze to prevent freezing in the winter. You need very little water since it rarely gets hot enough to need maximum heat transfer in the summer.

The other benefit to ethylene glycol is its resistance to boiling. When dissolved in water, it raises the overall boiling point of the coolant in the system.

[RichardM]

Originally Posted by curtis73

Let's say you live in Alaska where the temperatures rarely get above 80F and frequently get down to -30F. In that climate you need almost no water and almost all anti-freeze to prevent freezing in the winter. You need very little water since it rarely gets hot enough to need maximum heat transfer in the summer.

Not according to the information on the bottle antifreeze comes.

[jimmy101_again]

Standback, I'm going to use Science ...

What Richard said. The best anti-freeze protection comes from a mix of water and antifreeze. Pure water or pure antifreeze freeze at a higher temperature than do the mixes. (Google "colligative properties") Same for boil over protection, water + antifreeze is better than either one alone. Long story short, a mixture is always better than the pure liquids.

I've yet to see an engine which doesn't start due to freezing cooling liquid. The frost plug (don't know the proper English term) may have popped, and the engine will not cool as it should, but, if it's that cold, it's safe enough to drive it, at least short distances.

There is no such thing as a "frost plug". The American term for this myth is "freeze plug". Engine blocks have "core plugs" which people mistake for "freeze plugs". A core plug is an artifact of the casting process used in the manufacturing of the engine block. For casting reason the block needs a couple extra holes which are then sealed with core plugs. The holes are not there to prevent freeze damage and indeed won't.

True "freeze plugs" do occasionally occur in large engines but in a typical passenger car engine they don't exist, though nearly all engines have core plugs.

[ganzfeld]

The instructions on the bottle only say that so you'll buy more water. It's all a scam.

[jimmy101_again]

Originally Posted by ganzfeld

The instructions on the bottle only say that so you'll buy more water. It's all a scam.

Yep. And if you buy the pre-mixed stuff the cost is 90% of pure antifreeze even though the jug is half-filled with water.