Girls do that around dookie. Those hydrometers are plenty accurate enough. You really only have to be in the ballpark. Antifreeze keeps it from freezing, corroding, and lubricates. It doesn't transfer heat so well. Water transfers heat. 50/50 is sort the maximum balance between all those. You can go less antifreeze and still have plenty anti-corrosion and lubrication. And since you're in Largo you probably don't have to worry about freezing way below zero.
Tru dat, word to ya mudda. Don't forget the boilover protection! But yeah, it's pressurized and by the time you open the cap you oughta be well under 212F. Every once or twice a year I venture above the Mason-Dixon line... usually in the winter.
