50/50 is for cars in winter that will see temps approach freezing.
Here's the thing with coolant mixes. Nothing cools better than water. Except MAYBE water with water wetter added to it. I'm not sure and I'm using things I havent studied in a long time here. But When they measure the specific heat of materials and fluids water is the scale they use to measure it against.
So 50/50 robs some of the cooling ability from your system. BUT the properties of the coolant will change the Boiling temperature of the fluid.
Straight water boils at 100 degrees C or 212 F.
A 50/50 mix will be up around 230 degrees F.
So it is helpful to have coolant in the water IF you plan on letting your water get over 212F to begin with. So there's a Thermodynamic problem here. If you use all water can you keep the temps (give a 10% safety factor) below 190 degrees F?
If you do add coolant you lose some of the ability to cool the engine, but raise the BP.. Hmmm... Tough one. I don't remember my Thermo equations or formulas at all except
PV=nRT from Chem which I tutor sometimes..
What that basically says is Press.*Volume=n(constant)R(constant)*Temp.
So if your temp goes up either your pressure will go up or the volume will go up.
Once water or a coolant mix is changed to a gas (the only way the volume can go up) the specific heat changes. Now you're in trouble.
So you've got to be able to contain ad maintain your system at a higher temp to avoid boiling. So can you do that with all water?
Can you do it with Water Wetter and Water? Experiment and let us know.
Also maybe temp gauge and thermo cap arent accurate. Use a meat thermometer and or laser thermometer.
My temp gauge is WAY off. I'm on the P in temp when I'm at 200 degrees. I know this is fine, yet it's still unsettling.
Almost my whole post is basically reiterating what Tony D said. I really only banged out all that stuff above to see if I could still explain it properly and I'm not sure so googling "antifreeze mixes and boiling points"
got me this site which I haven't vetted but looks ok at first glance.
P.S. A lot of what water wetter does is removing the cohesive properties from water. Water is a trip. It's natures best coolant, and is both cohesive and adhesive. Adding soap to water removes the cohesive properties as well. This is really useful if you've got stagnant water with nothing living in it but Mosquitoes. If you add enough soap they can't land on the water and lay their eggs.