It all started so innocently: You're puttering around the garage on a crisp fall morning — checking for harmful low tire pressure and things like that — when you notice that your car's coolant tank is ...

Conventional green coolant lasts two to three years or 30,000 to 50,000 miles. Extended-life orange and red coolants last five years or 100,000 to 150,000 miles under normal operating conditions. The ...