Make certain the antifreeze will protect your car at the winter temperatures you’ll experience in your area. For most areas, you’ll need a 50-50 mix of coolant to water. You may think, “I’ll be extra good to my car, and give it 100% coolant.” Guess what? You’re wrong. The 50-50 mix has a lower freezing point. Not only that, but 100% coolant is less able to transfer heat away from your engine, and has been known to cause such nasty things as melted spark plugs of engine failure under the wrong circumstances.So, mix it up!