Of all the fluids in a car, few are more important than antifreeze. The vital liquid prevents a car's engine from suffering catastrophic damage and if it has outlived its usefulness, your car may be at significant risk. Despite it's crucial role, many people may not know how often they should change their antifreeze, which could lead to problems down the road.

It can be hard to know exactly when to change your antifreeze. There are a number of different schools of thought and some products tout to last longer than any other brand. However, most experts say that a good rule of thumb is to change the coolant every two or three years, or 30,000 miles. According to Yahoo! Autos, others suggest changing it every year, especially if you drive a car with an aluminum head, block or radiator.

Antifreeze needs to be changed because the chemicals that prevent corrosion can be used up over time. Though it can be hard to tell once it has lost its effectiveness, there are several ways to test how well the liquid is working. The most effective method is using test strips that identify the pH of the coolant. If the strips turns a certain color, the coolant should be changed. According to Yahoo! Autos, many suppliers provide such testing kits.

So once it's time to change the antifreeze there are a few options, but your best bet may be to take your vehicle to a car care center like the one at New Jersey State Auto Auction. Located in Jersey City, the center is open to the public and offers affordable service for regular maintenance as well as repairs.