Part replacement is a normal part of car ownership; after all the only way to avoid car repairs and maintenance is to park your car (which defeats the purpose of owning a car!). To help you decide when is the right time to replace important car and truck parts like brakes, spark plugs, and battery, we’ve put together this guide to help you take care of your car well.

Brakes

When to replace: Anywhere from 25-70,000 miles. The exact mileage depends on the type of brakes, driving style, type of vehicle, and amount of braking.

Signs your brakes need to be replaced:

• Squealing. It’s normal for brakes to make occasional squeaking sounds when they get wet. Consistent squealing occurs because of a warning indicator built in by the manufacturer when they are worn.
• Grinding or growling. If you hear a grinding noise when you press the brakes, the brake pads are worn down and metal is contacting metal. Basically, you have no more brake pads. Make an appointment with your mechanic.
• Longer stopping distance. If your brake pedal feels soft or if your car is taking longer to stop, your brakes may need to be replaced.
• Brake pedal that vibrates. If you feel an odd pulsating sensation when you press the brake pedal, contact your mechanic to find out if your brake rotors are warped and need to be replaced.
• A consistent pull to one side. If your car pulls to one side when braking, it could be a sign that your brakes need to be replaced OR it could be another cause (such as an alignment issue). Schedule an appointment with your mechanic to find out the cause and get it repaired.

Spark plugs

When to replace: Approximately 30,000-100,000 miles depending on the kind of spark plugs you choose. After your mechanic replaces your spark plugs the first time, stick to a strict schedule of spark plug replacement. Waiting too long to replace spark plugs can damage other parts of your vehicle. If you don’t know when it’s time to replace spark plugs, ask your mechanic to check your spark plugs at your next appointment.

Signs your spark plugs need to be replaced:

• Slow starting. Your battery may not be the cause of the slow turning over you deal with every time you try to start your car. Over time, the gap at the top of the spark plugs widens, slowing the spark needed for a quick start.
• Surges and engine misfires. When an engine misfires frequently, worn spark plugs can be the cause. Schedule an appointment to find out if your spark plugs need to be replaced.
• Sharp drop in fuel mileage. As your spark plugs wear down, they can cause the engine to run rich, increasing your trips to the gas station. Keep track of the amount of miles you get from every tank (simply press your trip odometer every time you fill up), and contact a mechanic as soon as the number of miles drops.
• Slow acceleration. If your car doesn’t accelerate as hard as it used to, it may be time to contact a mechanic to find out if your spark plugs are worn.

Battery

When to replace: An estimated 3-5 years. Batteries can give out at different ages, however, so it pays to be vigilant for signs of battery replacement. If your battery starts giving you warning signs within the warranty period, contact the store you purchased it from immediately.

Signs your battery needs to be replaced:

• Occasional jumping. If your car is leaving you stranded in your garage or when you’re out and about, have your mechanic check your battery at your next oil change.
• Rough starts. A long cranking every time you start up the car can be a signal of many problems, but the most obvious culprit is the battery.

 Air filter

When to replace: About every 15-30,000 miles depending on driving conditions. If you drive through dusty areas, your air filter is going to need to be replaced every 15,000 miles.

Signs your air filter needs to be replaced:

• Rough idling. If you hear odd sounds coming from your engine during idling or when driving, the air filter may be the cause.
• Reduced acceleration. A clogged engine is not going to perform as well. If you notice that your car seems sluggish, schedule an appointment to find out if your air filter is the cause.