Flushed and changed the coolant in my '99 Altima and the concentration is good to -50F. Since higher concentrations reduce heat transfer, should I reduce the concentration or just leave it be? i.e. is -50F much different from the recommended -35F from a heat transfer perspective?
Is -50F freeze protection too much antifreeze concentration?
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50/50 freezing point is -34
60/40 freezing point is -62
So you probably have around 55/45, which shouldn't be a problem at all. Some OE coolants are sold as 55/45 blend (I think Ford and Mazda do this)
I don't think there will be that much of an effect on heat transfer with such a small difference. If you really want to, you can take a little out with a turkey baster and just put that much plain water back in, but it really isn't necessary.
60/40 freezing point is -62
So you probably have around 55/45, which shouldn't be a problem at all. Some OE coolants are sold as 55/45 blend (I think Ford and Mazda do this)
I don't think there will be that much of an effect on heat transfer with such a small difference. If you really want to, you can take a little out with a turkey baster and just put that much plain water back in, but it really isn't necessary.
That’s more coolant than you need-but as long as you don’t overheat in very hot stop & go traffic, it won’t hurt anything. Really dependent on radiator, WP, and airflow conditions.
Since it has a water pump and a thermostat, the worst I expect to happen is that the coolant comes up to temp a little quicker because of the lower specific heat capacity or about the same because slightly lower conductivity but lower specific heat capacity, I'd think most cars have a cooling system designed to handle operating from the equator to the far north and should be fine with anything from like 40-60% antifreeze.
the viscosity of the coolant goes up significantly below freezing with increased concentration. That could introduce more stress on the waterpump and whatever drives the pump. But doesn't matter if you won't see very low temperatures.
Depends on how good the radiator, WP impeller, even hose condition & the amount of scale/etc. in the cooling system. MOST cars, it won’t matter-but a 22-23 year old Nissan, with unknown HG condition, or even the possible satanic exhaust manifold catalytic converter (that inevitably comes apart & disintegrates)-you never know…
I used 60/40 in my taurus while going to college in Utica, NY. I was heading home for the weekend after a major snowfall the previous night. With wind chill, it was -50*f. Wind was 30 mph.. I hopped in the car and let it warm up for 10 mins.. Waited for warmth from heater core, no warmth. Started out on the highway to head home, and no heat after 10 miles. No heat at all for an hour, my radiator was frozen solid. There were no ill effects from the freeze, I thought for sure there would have been a crack in the rad, but nothing.
Moral of the story: If it gets below zero in your area, even just once a year, leave room for wind chill temps. I use 70/30 now, but there is a point in concentration, no ill effects in the summer that I've noticed from the 70/30.
Moral of the story: If it gets below zero in your area, even just once a year, leave room for wind chill temps. I use 70/30 now, but there is a point in concentration, no ill effects in the summer that I've noticed from the 70/30.
That’s not how wind chill works.
Wind will not, and can not, cool your car below ambient temperature. That would be a violation of several physics principles.
Wind chill was invented to describe the effect of temperature and wind on exposed human skin.
Wind chill describes how cold it feels to a person, who is above ambient temp.
But no, your car didn’t cool to the temperature of the wind chill. It cooled to the actual temperature.
Also in the continential US there's nowhere where beyond 60/40 should ever be necessary, 50/50 is good enough almost everywhere where it gets "cold," there's only a handful of places where 60/40 should ever be necessary, 70/30 is completely unecessary.
So if a bare piece of skin at -30*f has a wind chill factor stated at -50*f, that will be a different than a piece of metal, ie the radiator? I just don't buy that.
Your saying if its 50*f outside, and you're heading down the road at 60 mph, the windspeed across the radiator has zero cooling effect, and that the coils in the radiator will only experience 50*f? This is a new concept for me. Off to do some research!
Some inanimate objects, such as car radiators, have an internal heat source and are not impacted by wind chill. This is, of course, provided that your radiator does not have leaks and operates normally. For wind chill to be a factor in the operation of a car radiator, a heat loss or transfer must occur. While wind chill may cause the temperature of the antifreeze in the radiator to drop, the radiator itself, like most simple inanimate objects, will not become colder than the temperature of the air.
So this thermodynamics website does indeed state that wind chill does effect the cooling of the radiator fluid, but not the radiator itself. This is where I'm kinda confused. If the radiator fluid is cooled below the temp of the surrounding radiator, does it than enter your engine cooler than your radiator, or I would tend to think the radiator would heat it back up to engine temp?
I am way overthinking this..
I just run 70/30 in my cars.. The northeast is a fickle woman. 5 years ago we had three weeks straight of -18*f, with a few -29*f mornings around there.
I don't want to wake up to a bomb cyclone at -45*f and not have rad fluid protection for it. As I stated, I'm that guy that always overdoes ****.
Learned something new about wind chill today! Thanks Astro 14
I don't want to wake up to a bomb cyclone at -45*f and not have rad fluid protection for it. As I stated, I'm that guy that always overdoes ****.
Learned something new about wind chill today! Thanks Astro 14
Try the Northern Adirondacks, they've plenty of cold ass days up there. What's the reason just not to use 70/30? There's no harm, and the extra antifreeze may help boil over protection, and help the water pump.
The reason not to use 70% polyethylene glycol coolant is that it coud make your car run hotter as a coolant/water mixture that high has less capacity to absorb and hold heat. If your cooling system has enough excess cooling capacity that this never happens, then 70/30 coolant to water ratio is probably not a problem.
So it raises the boil over temperature to 235*f, but does not absorb heat as well as other mixtures?
You live in DC. It does not get hot there. Leave it and don't worry about it.
No problems with 60/40. We do it a lot up here. 
This Dexcool has was close to 60/40 and has been in my Chevy LS engine for the last 3 years.
This Dexcool has was close to 60/40 and has been in my Chevy LS engine for the last 3 years.
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