Any better cooling efficiency with a 70/30 mix of antifreeze versus 50/50? How about if I add water wetter in the mix?
No, 50/50 or 55/50 is pretty much optimum. The only place I have ever read anything about "water weter" is on this board and to me it is something akin to snake oil. Some people swear by it and some of us shake our heads.
What are you putting it in ? On any of my old cars, I aim for a 50/50 mix...but I also keep a constant check on the mix I'm adding with a good antifreeze tester. For my area, St. Louis, I make sure my final mix can take me to about 34 below. Then, I always keep at least a back-up gallon of the same mix in the trunk with me at all times...even in my Daily Driver, in case I need to "top off". Hope this helps. But like I said, make sure you use a quality tester when you mix and you should be okay. Jonnie www.legends.thewwbc.net
Been using 70/30 Water to Coolant for 10 years. Haven't had any problems. Don't drive in the winter, That ratio takes me down to about 10 degrees. Never gets below freezing in my garage. Water has more capacity for carrying off btu's than coolant and gives them up quicker in the rad. Engine temps never get above 190 still using radiator built in 1946.
As far as cooling efficiency, pure water has a higher specific heat compared to water-antifreeze mixtures. EG or PG antifreeze depresses the freezing point and elevates the boiling point. Rust inhibition is another common function of modern antifreeze. mixture table: http://homepage.usask.ca/~llr130/physics/HeatCapcityOfAntiFreeze.html
As yellow dog says, water has the higher heat capacity. However that's pretty well moot as the limiting factor in cooling engines is usually not the transfer of heat to the radiator, but rather transferring heat from the rad to the air.
We've started putting in a bottle of Bar's Leak Anti Rust additive (not the Bar's leak for stopping leaks). It has really made a difference in how clean the coolant and engine parts stay. We just drained the coolant out of an engine to put a different intake on it and it came out as clean as the day we put it in two years ago. We previously had issues with the spring in the radiator hose rusting and since using the anti rust stuff it looks brand new too. Supposedly it has some water pump lubrication properties too. Don
Putting it in a stock 60 Bird. It will run "hot" in stop and go traffic but OK on street. The stock gage needle will go over to the "P" in temp. I am going to get a temp gun and check the temp at that indication. The owner is concerned about it. Already added shroud and 180 t-stat.
The only thing a 70-30 mix does is raise the boiling point of the coolant a little. I have used 50-50 for years with no problems in single digit temperatures. If your dealing with a heating issue, that concern needs to be dealt with first. If it will stay cool with straight water it doesn't matter what a mix will do. I use Water Wetter not because of a heat issues but for better water circulation and pump lubrication.
I use a mix, which is 50/50 and a bottle of "Purple Ice". I heard from a speed shop that "Water Wetter" wasn't good for aluminum radiators. I did spring a leak in an aluminum radiator so now I use copper/brass 4 rows triple pass radiators and I run A/C.
What is it that you're trying to accomplish? As someone said earlier, water is the best coolant. You can run straight water (distilled) if you have no freezing concerns, but you need to have something added to lubricate as well as inhibit rust. Most vehicles run a 50/50 mix and will never see anything close to -34F.
From the conditions you describe the type of coolant isn't going to make much difference but I'd still run a 50/50 mix. I have to think that the car has something else going on causing it to get hotter than it should in traffic. Have you checked the actual condition of the inside of the radiator? Have you checked the radiator and what ever is in front of it such as the ac condenser to make sure that they are clean on the outside and the air can flow though them? I bought a van with a burned up engine that had over half the radiator covered with trans fluid that was packed solid with dirt so it blocked off most of the air that should have gone through the radiator. It had an external trans cooler with a leaky hose. Around my home area the radiators can get plugged up in front with bugs in the summer time and cause a rig to overhead. Also is the fan clutch working correctly, not cooling well in traffic is an indicator that may not be working right. Also the off brand ones don't always work well when they are new. If it had a recent waterpump change did they get the right waterpump on it? Those are just a few things to look into if you haven't done so already. I do the same as Jonie King in that I premix my coolant and carry a jug in each vehicle. It doesn't take a rocket scientist to pour half of one jug into an empty jug and fill each back up with water to have two gallons of coolant mixed up. As for those Phoenix guys who say they don't need antifreeze and just run water year round. Noon temp yesterday in Phoenix, photo came from a friend vacationing there who froze her butt off at the golf tournament. I'd imagine that there were a few cars sitting on the side of the road with frozen radiators and steam coming out this past weekend.
He doesn't drive the car in the winter an taking it down to 10 above is plenty good for a car that stays in a garage and never gets out where the wind chill against the radiator would cause it to freeze up going down the road. Actually pretty common with guys who don't drive a rig in the winter as it won't freeze up sitting still and not running with that mix. I'm like you I just go 50/50 but in my area I have seen it -20 in the past and drove my 48 in that -20 35 miles one way to work. The truck did a lot better than I did on that one.
This discussion is moot till you find out what the needle over the P means in terms of actual degrees of coolant. In other words how hot is hot if hot at all? Putting in a 180 degree t stat will have no effect on the terminal temp. All that does is keep coolant in the engine until it reaches 180 degrees, and has little effect on "running temp". The other factor is, is it a pressurized system, and what pressure, as pressure also determines the boiling point. So if the engine is running 190, at O pressure, on straight water, your cushion to boiling over is 22 degrees at sea level. If you are running 190 degrees with 50/50 and 7 lbs of pressure your boiling point is in the 240 neighborhood, and your cushion to boil over at 190 is now 50 degrees. Which doesn't make 190 hot in comparison does it? Without knowing the facts of the "overheating" you can not have a meaningful discussion of the situation.
Ford did a study many years ago and found that a mix of 10 percent antifreeze is all you need in most cases.(North Dakota maybe not) They also found that antifreeze created a barrier to the transfer of heat from the block to the coolant. Pure distilled water is best coolant. Pressurizing the coolant system will raise the boiling point. This is good for the hot spots around the combustion chamber. Antifreeze is a lousy coolant but does keep the coolant from freezing. In Houston Texas 10 percent antifreeze is almost too much. Your results may vary.
Just a point re 50/50 water/antifreeze, this is by weight not volume. The difference probably doesn't matter to anybody. Also although pure water has a higher heat capacity it isn't as functional in the system. By antifreeze raising the BP in the system, the mixture remains in better contact in the block, heads, etc with less cavitation and site vaporization. Cavitation and vaporization become the site of metal removal over time and can be as devastating as corrosion
As far as water wetter goes, I use it and it helps me keep the temp down below 190. The reason water wetter works is because it lowers the surface tension of the coolant mix. the lower surface tension allows the coolant to draw heat off more efficently by actually getting the coolant fluid against more surface area by filling in the pores of the cast iron instead of bridging across the pores.
Probably not likely to happen to anyone in this crowd but a 70/30 mix will thicken up like jello at minus 40.