Northern MN here, we saw well into the -40's last winter without the wind chill. My Jeep sat all winter with 50/50 mix and didn't have any issues, all my snowmobiles are however a 60/40. I did get a little worried a few times but I believe there is a enough thermal mass in an engine block that the coolant temp never drops that low, it probably held fairly steady somewhere between the daytime high and the low which was maybe -30
Extreme Cold Anti-Freeze
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Years ago it was bulky 'down' for winter clothing, Now 3M Thinsulate does a nice job. We can usually dress for cold, but for hot and especially added with humid, no relief but inside with the A/C. In the Twin Cities 50-50 is fine, but I'd agree to more like 60-40 'up nort'
I wasn't even talking about the twin cities. I grew up in Annandale, which is west of the cities about 60 miles. In places like Arizona it gets up to 110 F on the average day, and there are people there that love it. Even here in MN there are those people that every 90+ day its "Oh I love this beautiful weather so much." No, its not beautiful. I just figure those people work indoors in the AC.
Originally Posted By: 20pss
I am a little farther south near brainerd, so it was a little warmer. I remember -32 F low a few days last year. Wind chills were far colder than that. I don't mess with oil weights much. In my truck, I have always ran 5w-30. It has over 225,000 miles of beating on it. My car I used 5w-20 and had no problems. If anything, I go to 10w in the summer. A proper warm up is the key. You usually cant see out your windshield for 5 minutes anyway. The thing is with that chart, is that is when the coolant is brand new. As you said, some never add coolant (technically you shouldn't have to), but I am not one. I stay on top of maintenance, and rarely have car problems. The other thing is I have heard the freezing point comes up with age. I don't like flushing my cooling system if I don't have to. I think I'll try prestone at 60/40. Thanks a lot for that chart. One thing I forgot to ask is how does the radiator cap affect the freezing point, if it does at all. My guess is it does not, and only affects the boiling point. My car has a sealed system anyway. I think my truck has a slightly higher pressure cap than standard.
The freeze protection is almost exclusively a matter of the base fluid. That shouldn't change unless there's some sort of preferential loss of the glycol over the water.
The sole reasons you'd want to change the stuff is to replenish the additives, remove any built up gunk, and/or alter the concentration.
I am a little farther south near brainerd, so it was a little warmer. I remember -32 F low a few days last year. Wind chills were far colder than that. I don't mess with oil weights much. In my truck, I have always ran 5w-30. It has over 225,000 miles of beating on it. My car I used 5w-20 and had no problems. If anything, I go to 10w in the summer. A proper warm up is the key. You usually cant see out your windshield for 5 minutes anyway. The thing is with that chart, is that is when the coolant is brand new. As you said, some never add coolant (technically you shouldn't have to), but I am not one. I stay on top of maintenance, and rarely have car problems. The other thing is I have heard the freezing point comes up with age. I don't like flushing my cooling system if I don't have to. I think I'll try prestone at 60/40. Thanks a lot for that chart. One thing I forgot to ask is how does the radiator cap affect the freezing point, if it does at all. My guess is it does not, and only affects the boiling point. My car has a sealed system anyway. I think my truck has a slightly higher pressure cap than standard.
The freeze protection is almost exclusively a matter of the base fluid. That shouldn't change unless there's some sort of preferential loss of the glycol over the water.
The sole reasons you'd want to change the stuff is to replenish the additives, remove any built up gunk, and/or alter the concentration.
Here is a kind of spin off question. How will a coolant system flush affect barsleak stop leak? I put it in my truck to fix a small head gasket leak into cylinder 4, and it worked. It has been holding for 2 years. If I flush the system, will it possibly open up the leak? I guess the better question is does that stuff harden, or does it just kind of plug the hole?
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It may be disturbed by the flush.
Where is the mixture point (again, as I forgot) where the freeze point actually gets HIGHER with too much af/coolant? (i.e.; 80/20 coolant/water??)
Originally Posted By: dailydriver
Where is the mixture point (again, as I forgot) where the freeze point actually gets HIGHER with too much af/coolant? (i.e.; 80/20 coolant/water??)
All I could find was a graph based on percentage weight and not volume. However, it's pretty clear that there's a point where increasing the proportion of glycol will raise the freezing point.
http://www.huntsman.com/performance_prod...ochure_full.pdf
It's on page 22. It looks like it's around 70% glycol by weight, although I think glycol is less dense than water.
Where is the mixture point (again, as I forgot) where the freeze point actually gets HIGHER with too much af/coolant? (i.e.; 80/20 coolant/water??)
All I could find was a graph based on percentage weight and not volume. However, it's pretty clear that there's a point where increasing the proportion of glycol will raise the freezing point.
http://www.huntsman.com/performance_prod...ochure_full.pdf
It's on page 22. It looks like it's around 70% glycol by weight, although I think glycol is less dense than water.
Without enough water in the system (30%+) you will likely overheat due to the poor thermal conductivity and volumetric heat capacity of the pure coolant.
Also more coolant increases the viscosity of the overall mixture increasing power consumption and making the system work harder.
If you need the freeze protection for the - 40 winters you want 60/40 AF to water, but if you can get away with it go 40/60 AF to water which should be good down to - 12F.
Check out this link, it has some information about what I was talking about.
Dispelling the Myths of Heat Transfer Fluids Kevin Connor – The Dow Chemical Company
Also more coolant increases the viscosity of the overall mixture increasing power consumption and making the system work harder.
If you need the freeze protection for the - 40 winters you want 60/40 AF to water, but if you can get away with it go 40/60 AF to water which should be good down to - 12F.
Check out this link, it has some information about what I was talking about.
Dispelling the Myths of Heat Transfer Fluids Kevin Connor – The Dow Chemical Company
I'd just point out that you're almost never dealing with only ethylene glycol and water. There's a little bit of other stuff that may affect the numbers slightly. Some coolants use a little bit of diethylene glycol, which has a slightly higher freeze point alone with water, although I don't know if there might not be some sort of "synergistic effect" that would lower the freeze point. There might also be some minor effects from the corrosion inhibitors. I don't think they all freeze up per se, but I think it slightly affects the proportion of coolant to water.
Sounds like 55-60% coolant is reasonable concentration for your vehicle. If you have a drain cock on the radiator, it would be easy to drain off some of the higher concentration mix in the spring and top off with distilled water for a more efficient summer ratio. Come fall next year, repeat, topping off with fresh coolant to get back to a higher concentration.
Unless you are using a refractometer to test the coolant protection, all this talk is academic. And lowering the freezing point also raises the boiling point so going to even 70% coolant isn't a problem in the summer.
Originally Posted By: atikovi
Unless you are using a refractometer to test the coolant protection, all this talk is academic. And lowering the freezing point also raises the boiling point so going to even 70% coolant isn't a problem in the summer.
Boiling point isn't that important in summer. It might raise the boiling point, but it would also reduce the ability to cool. I know there can be localized hotspots that might boil over, but the overall ability to cool is what's important in summer. It's been mentioned that adding too much glycol increases the viscosity, and therefore flow rate. It also reduces the heat carrying capacity of the mixture.
A lot of people use about a 40% concentration in summer. It wouldn't be a problem in places where it never freezes or even where it doesn't get subzero. Around here it might even be OK to go even lower since it might barely get to freezing about every other year. I remember seeing a Subaru service bulletin that said something like 36% was the lower limit, and that was to ensure adequate corrosion inhibitors were in the system. I've also heard that less than 25% can lead to microorganisms growing, although I'd think that regularly running an engine would kill them off.
Unless you are using a refractometer to test the coolant protection, all this talk is academic. And lowering the freezing point also raises the boiling point so going to even 70% coolant isn't a problem in the summer.
Boiling point isn't that important in summer. It might raise the boiling point, but it would also reduce the ability to cool. I know there can be localized hotspots that might boil over, but the overall ability to cool is what's important in summer. It's been mentioned that adding too much glycol increases the viscosity, and therefore flow rate. It also reduces the heat carrying capacity of the mixture.
A lot of people use about a 40% concentration in summer. It wouldn't be a problem in places where it never freezes or even where it doesn't get subzero. Around here it might even be OK to go even lower since it might barely get to freezing about every other year. I remember seeing a Subaru service bulletin that said something like 36% was the lower limit, and that was to ensure adequate corrosion inhibitors were in the system. I've also heard that less than 25% can lead to microorganisms growing, although I'd think that regularly running an engine would kill them off.
Originally Posted By: 20pss
I will say that I have ran 50/50 of parts store brand coolant my whole life, and never had a problem. Last winter it made me consider if I was doing enough. Here in Minnesota, temps got below -30F a few times by me, and parts of the state went below -40F. I never had a problem, but I heard of numerous reports of cracked radiators, overheating, or other problems. Damaged heater cores seemed to be a big one.
While keeping your cooling system well maintained, with coolant/antifreeze that is fresh and of the proper concentration, is very important, many of the problems you mention can also be avoided by allowing an engine to get up to temperature before driving.
Over 30 years ago I remember working in the cold of winter, at a plant that was in the Western Utah desert. When we got off work on graveyard or swing shift, it would sometimes be in the below 0° F temperatures. And it was so odd to be driving home, and see a co-worker pulled off the side of the road with an overheated engine. At that young age, I didn't understand how a car could overheat in the dead of winter.
My carpool friends explained that in conditions that cold, it is very important to allow the engine to warm up to where the thermostat opens before driving, particularly at highway speeds. If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you wait until the thermostat opens, before driving, then the coolant is flowing through the radiator, and is is warm enough that the cold air will not freeze up the radiator.
Keeping a car in a garage, or using a block heater, all help greatly. But we can't always do that. There are times where our car may sit at work, or at an airport, etc, where there are no garages or access to plug in a block heater. At those times, it is good to remember to properly warm up a car before driving in winter months.
I will say that I have ran 50/50 of parts store brand coolant my whole life, and never had a problem. Last winter it made me consider if I was doing enough. Here in Minnesota, temps got below -30F a few times by me, and parts of the state went below -40F. I never had a problem, but I heard of numerous reports of cracked radiators, overheating, or other problems. Damaged heater cores seemed to be a big one.
While keeping your cooling system well maintained, with coolant/antifreeze that is fresh and of the proper concentration, is very important, many of the problems you mention can also be avoided by allowing an engine to get up to temperature before driving.
Over 30 years ago I remember working in the cold of winter, at a plant that was in the Western Utah desert. When we got off work on graveyard or swing shift, it would sometimes be in the below 0° F temperatures. And it was so odd to be driving home, and see a co-worker pulled off the side of the road with an overheated engine. At that young age, I didn't understand how a car could overheat in the dead of winter.
My carpool friends explained that in conditions that cold, it is very important to allow the engine to warm up to where the thermostat opens before driving, particularly at highway speeds. If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you wait until the thermostat opens, before driving, then the coolant is flowing through the radiator, and is is warm enough that the cold air will not freeze up the radiator.
Keeping a car in a garage, or using a block heater, all help greatly. But we can't always do that. There are times where our car may sit at work, or at an airport, etc, where there are no garages or access to plug in a block heater. At those times, it is good to remember to properly warm up a car before driving in winter months.
Originally Posted By: BHopkins
If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you have the proper concentration of antifreeze for the climate, that will never happen.
If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you have the proper concentration of antifreeze for the climate, that will never happen.
Originally Posted By: atikovi
Originally Posted By: BHopkins
If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you have the proper concentration of antifreeze for the climate, that will never happen.
Pretty much. If the ambient temp isn't below the freeze point of the coolant in the system, this won't happen. Mind you, if the rad has an ice film on the outside, that could evaporate a bit and cool it slightly once you get airflow over it, but that won't be enough to matter.
I think the coldest I've ever driven the Jeep in was -5* F. I've never let it warm up more than 30 - 60 seconds at that temp (unless it was necessary to get heat for defrosting), never had an issue with 50/50 coolant mix.
Originally Posted By: BHopkins
If you drive before the engine warms up, the cold air passing through the radiator can turn the antifreeze, that is currently standing still in the radiator, to turn to a slush, or even almost ice. Once the radiator does open up, the ice blocks the circulation and the engine overheats.
If you have the proper concentration of antifreeze for the climate, that will never happen.
Pretty much. If the ambient temp isn't below the freeze point of the coolant in the system, this won't happen. Mind you, if the rad has an ice film on the outside, that could evaporate a bit and cool it slightly once you get airflow over it, but that won't be enough to matter.
I think the coldest I've ever driven the Jeep in was -5* F. I've never let it warm up more than 30 - 60 seconds at that temp (unless it was necessary to get heat for defrosting), never had an issue with 50/50 coolant mix.
You could always pull a sample if you don't service your own vehicle to make sure you have at least 50% Antifreeze for the really cold parts of the US.
Originally Posted By: atikovi
Unless you are using a refractometer to test the coolant protection, all this talk is academic.
Agreed. A $20 refractometer is the way to go. Coolant hydrometers are useless at best.
Unless you are using a refractometer to test the coolant protection, all this talk is academic.
Agreed. A $20 refractometer is the way to go. Coolant hydrometers are useless at best.
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