The general rule is to replace your car's coolant every 30,000 miles or every 5 years, whichever comes first. However, this is a starting point. The most accurate interval is specified in your vehicle's owner's manual, as some modern cars can extend to 100,000 miles or 10 years. Neglecting this service can lead to engine overheating and severe damage.
Coolant, also known as antifreeze, does more than just regulate temperature. Its corrosion inhibitors break down over time and with mileage. If these additives deplete, the coolant becomes acidic and can corrode the radiator, water pump, and heater core from the inside out.
For clarity, here is a sample of replacement intervals from various automakers. This demonstrates why checking your manual is non-negotiable.
| Vehicle Manufacturer | Recommended Coolant Change Interval |
|---|
| Honda & Acura (older models) | 30,000 - 60,000 miles / 3-5 years |
| Toyota & Lexus (older models) | 30,000 - 60,000 miles / 3-5 years |
| General Motors (GM) | 150,000 miles / 5 years |
| Ford (most models) | 100,000 miles / 5 years |
| Hyundai & Kia | 60,000 - 120,000 miles / 5-10 years |
| BMW (Long-Life Coolant) | 120,000 miles / 10-12 years |
| Mercedes-Benz | 120,000 miles / 10-12 years |
| Chrysler, Dodge, Jeep | 100,000 miles / 5 years |
A visual inspection can also provide clues. Fresh coolant is typically bright green, orange, pink, or blue. If the fluid in your overflow tank is rusty, muddy brown, or has particles floating in it, it's time for a change regardless of mileage. For most drivers, following the factory schedule is the safest and most cost-effective strategy to prevent expensive engine repairs.
