1. Oil lubricates and cleans the engine's moving parts, and it all the heat and debris eventually breaks it down.
   Because oil goes bad over time, like milk.
2. To increase fuel economy
   Because it fuels our vehicles.

Oil has several key functions, including lubricating moving parts and washing away contaminants. Over time, the heat from the engine breaks down the oil's viscosity and the contaminants become too dense for the oil, causing it to lose its effectiveness. This is when it's time to change the oil.

1. It will damage the engine.
   It can reintroduce contaminants or even clog.
2. The filter will eventually expand and leak.
   The filter will become too heavy and fall off.

The oil filter removes all the contaminants from the oil as it flows back through the engine. If left unchanged, these contaminants can eventually become too much for the filter to handle and can flow back into the engine. In severe cases, the filter can even become clogged and cut off the flow of oil to the engine.

1. It changes the angle and rotation of the tire to help even out tire wear.
   It keeps your car driving straight.
2. Allows you to line up all the names on the tires
   It prevents vibrations.

Each corner of your vehicle has a slightly different angle for your vehicle's tire to sit at. Leaving it in this angle for too long can cause premature wear. Rotating the tires ensures you constantly change the way the tire contacts the road.

1. Your wheels may fall off.
   You could blow out your tires.
2. You will get excessive wear in one area of the tires.
   You will damage the suspension.

Leaving your tires in the same spot on the vehicle will also leave them contacting the road at the same angle, which is never exactly perpendicular to the road. This eventually leads to excessive wear in the spot of the tire that bears the most weight. This can dramatically shorten the life of your tires and void any warranty.

1. To prevent vibration while driving
   To keep all things equal
2. To ensure your car's weight is distributed evenly
   To keep the suspension well-balanced

The tire manufacturing process is an imperfect one that results in natural heavy spots in the tire. Balancing the tire counters these heavy spots with small wheel weights. If you do not balance your tires, the vehicle will shake at certain speeds and potentially cause damage to the chassis.

1. They are inside the engine and hard to replace.
   To keep fuel economy at its peak
2. A broken belt can leave you stranded on the side of the road or even cause severe engine damage.
   So your air conditioner runs efficiently

Belts are often out of sight and out of mind, but checking them frequently can catch early cracking that can result in sudden breakage if left unchanged. Your car's accessory belts power the alternator and, in some cases, the water pump and fan.

1. Bugs are attracted to it and land in it.
   Oil gets into the system and contaminates it.
2. It simply breaks down over time.
   It absorbs water.

Brake fluid is hygroscopic, which means it absorbs water from the surrounding atmosphere. This water can impact its ability to function properly and result in brake system damage or failure.

1. Air can get into the lines, or the brake components can rust.
   The brakes will squeal.
2. Premature brake pad wear
   Warped rotors

Brake fluid absorbs water from the atmosphere, and water will lower the brake fluid's boiling point. This can result in the fluid boiling and introducing air into the system or damaging the rubber seals within the system. Water can also cause the brake line and components to rust from the inside.

1. Loses its heat-absorption and lubricating qualities
   It's what the owner's manual says.
2. It will start to leak.
   You really don't need to .

Coolant goes through constant heating and cooling, which can break down its viscosity. This breakdown reduces its ability to absorb heat and lubricate the cooling system's moving parts. Changing the coolant as the manufacturer recommends will prevent these breakdowns from causing any overheating issues.

1. To keep your car from bouncing too much
   To prevent tire wear and damage
2. So the tires look even
   To keep my warranty valid

Tires are very sensitive to pressure, and having the pressures off can result in excessive tire wear. Always set your tires to the "Cold PSI" setting noted on the tire placard inside the door.

1. You will see excessive wear on the outer edges of the tires.
   They will bulge and explode.
2. They will squeal all the time.
   Excessive vibration

Underinflated tires hold most of the vehicle's weight on their outer edges. This unbalanced weight distribution can cause excessive wear on the outer edges of the tires.

1. They will explode.
   The wheels will rub.
2. The center section of the tire will wear quickly.
   Nothing at all

Overinflated tires will bulge in the center, putting most of the vehicle's weight on this part. This will cause the center portion of the tire to wear out quicker than the rest of the tire.

1. To pull the chassis back within the manufacturer's specification and prevent tire wear
   To make sure the body is straight
2. To prevent vibrations
   To keep your car's ride smooth

Rough roads and normal driving slowly pull the chassis out of alignment. This causes the tires to sit at an angle the manufacturer did not intend them to and can cause excessive tire wear. Regular alignments keep the chassis within spec and prevent this issue.

1. The car will shake viciously.
   The tires will continue wearing out at a high rate.
2. Nothing. Alignments are scams.
   The body can warp.

If you continue driving without having your vehicle aligned regularly, your tires will constantly sit at an angle the manufacturer did not intend. This will cause excessive tire wear and lead to you replacing tires more frequently than you should

1. Easier to start the vehicle and it may run better
   They look good when they are shiny.
2. Because they are smoother.
   They allow my stereo to play louder.

The battery is the heart of your vehicle. All the power runs through it and having corroded terminals interrupts the flow of power. Keeping the terminals clean allows power to flow freely, making it easier to start the vehicle, and may even run better too.

1. Frequently dumping soda on them
   Anti-corrosive spray
2. Weekly cleanings
   Covering them with a cloth

Auto parts stores sell an anti-corrosive spray that helps keep corrosion to a minimum while not interfering with the flow of energy . Applying this according to the instructions on the spray will help minimize corrosion and keep your battery in top shape.

1. It make your car look good.
   It adds a protective boundary between environmental elements and your car's paint.
2. Professionals say to do it.
   It's really not that important.

Wax adds a thin coat that protects your car's expensive paint job from all the environmental fallout in the sky. Instead of attaching to your car's paint and potentially causing pitting and other damage, the fallout lands on the wax and is easily swept away by water.

1. Nothing. The timing belt never really needs replacing.
   You may lose a little power, but the car is fine.
2. It can break and potentially cause major engine damage.
   Your "check engine" light will stay on.

The timing belt is what synchronizes your car's valves with the piston stroke. If the belt snaps, the valves can fall and contact the piston, which can cause major engine damage. Replacing the timing belt at the recommended intervals can prevent this issue.

1. These items contact the timing belt and can fail, causing your new timing belt to break.
   You really don't need to.
2. Because they are all part of the belt.
   Because everything looks better when it's all new.

The timing belt tensioners, pulleys and the water pump all make direct contact with the belt and can wear out over time. While you have the belt off, it is best to replace these items to prevent their failure from damaging the new belt. Many timing belts come in kits that already include these parts.

1. To keep the steering and suspension system lubricated
   To stop squeaking
2. To make it easier to steer
   To make the vehicle run better

Many trucks and SUVs use greasable front-end components that require regular greasing. Failure to grease them regularly can cause excessive wear and eventual failure. Some of the components you need to grease include the ball joints, steering rack, steering linkage and tie rod ends.

1. Nothing really
   Squeaking and eventual failure
2. It gets hard to steer.
   The whole front end falls out.

As front end parts run dry, they will begin to squeak louder and louder. Eventually they will rub metal against metal, which causes them to become loose and eventually fail. Best case, they fail but remain intact. Worst case, they fail and you can lose control of the vehicle.

1. It will clog and not allow you engine to not breathe.
   It will eventually fall apart and cause damage.
2. It can catch fire.
   It doesn't need replaced -- it's only a recommendation.

The air filter plays a huge role in keeping sand, dust, bugs and other debris out of the engine. Over time, these contaminants get caught up in the filter and clog it. If the right amount of air cannot get into the engine, it can reduce power and fuel efficiency.

1. Without it, bugs will get inside the car.
   It makes everything smell good.
2. It becomes clogged and restricts the flow of air through your heating and cooling ducts.
   A clogged filter will kill your A/C.

The cabin air filter prevents pollen, dust and other debris from entering the cabin. Over time, these contaminants build up and clog the filter. While a clog typically causes no mechanical failures, it can redistrict the flow of warm or cold air into the cabin, making it uncomfortable.

1. They are designed to fail.
   Heat and cold wreaks havoc on them.
2. They never really go bad.
   Water damage

Your car's windshield wipers catch the brunt of all the heat and cold the environment throws at your car. While these rubber blades can handle a lot of abuse, they eventually dry out and crack, which causes them to streak water across the windshield instead of wipe it away.

1. They can dig into the rotors and cause caliper damage.
   Nothing really. As long as the car stops, you're all good.
2. Cause wheel damage
   Damage the suspension

If you wait too long to replace the brake pads and the metal backing plate of the pad contacts the rotor, this can dig large grooves into the rotor and force you to replace the rotor too. A low pad level also forces the caliper piston to overextend, which can cause the piston to become jammed, forcing you to replace the entire caliper, too.

1. Nothing. Slapping on new pads is good enough.
   You can damage the brake lines.
2. The car won't stop.
   The pads can wear quickly and stopping distance may be longer.

The brake pads need a rough surface to grab for maximum effectiveness, which is why we resurface rotors. Failure to resurface rotors forces the pads to grip smooth rotors or those with uneven surfaces, resulting in longer stopping distances or uneven pad wear.

1. They soften over time and can burst unexpectedly.
   To check their tightness
2. To make sure fuel flows freely
   To make sure they are still there

The constant heating and cooling your car's hoses go through can lead to them softening over time. As they soften, the risk of bursting increases. Catching a soft hose early can prevent them from bursting and potentially causing overheating.

1. It prevents calipers from sticking.
   You don't need to.
2. It keeps them shiny.
   It lets the pads move freely.

The caliper slides are what allow the caliper to slide back and forth during braking. With each brake job, you need to lubricate these slides to allow the calipers to move freely. With dry slides, the calipers can stick and cause excessive brake pad wear or vibration.

1. It loses its ability to cool.
   It get sticky.
2. It becomes contaminated and loses its viscosity.
   It just gets old.

Transmission fluid has many responsibilities: cleaning, lubrication, cooling and hydraulics. As it ages, the fluid becomes dirty and loses its ability to lubricate under high heat. Changing the fluid restores these properties and prevents damage to the transmission.

1. The fluid loses its ability to lubricate, clean and cool the transmission, causing the transmission to overheat and break down.
   It turns black, but nothing bad happens.
2. The filter clogs.
   The transmission locks up immediately.

The transmission fluid has many responsibilities, so it can fail in many ways. This is why it is key to change it right on schedule with what the manufacturer recommends. Generally, when the transmission fluid becomes contaminated it initially loses its lubricating and cooling properties, which starts the downward spiral of transmission failure.

1. The electrodes wear out or become dirty, making the spark colder.
   To keep the battery charged
2. To make the engine run better
   To enhance fuel economy

Through normal wear and tear,spark plugs lose small amounts of material from their electrodes and these electrodes collect dirt and debris. Over time, this causes the spark jumping between these electrodes to weaken, making the engine less efficient. Replacing the spark plugs at the manufacturer's recommended interval restores the hot spark.

1. To make the car start faster
   You don't need to.
2. They become brittle over time and replacing them can prevent complete failure.
   They just need it.

As spark plug wires age, the constant exposure to the engine's heat can cause their rubber covers to become brittle and crack easily. When removing the wires from the plugs, you can break the cover without realizing it, causing a short you won't notice until after you've already installed everything.

1. It's what the manufacturer says to use.
   It maximizes lubricating properties and efficiency.
2. Too heavy oil will weigh down the car.
   Weight actually does not matter.

Manufactures choose an oil weight for their engines that delivers the best combination of lubricating properties and efficiency. Straying from this weight of oil can cause decreased performance and efficiency.

1. Each coolant type has different additives and lubricating qualities.
   You can actually run the basic green stuff in any car.
2. So you spend more money
   The wrong one will make your car stall.

Manufacturers design cooling systems with specific fluid types in mind. While many share the same fluids, there are some with specific types. These generally have different additives to extend their useful lives and lubricate the cooling system's moving parts more effectively.

1. Their wear can sneak up on you and not rear its dangerous head until you hit bad weather and need good tires.
   Tires are expensive, so checking them regularly lets you save up with plenty of time to spare.
2. To make sure they are still round
   To make sure one is not blown out

Tire wear and tear sometimes goes unnoticed until you hit bad weather and start sliding all over the place. You can catch excessive tire wear or damage before these issues arise by just taking a look at your tires and checking their tread depth once every few weeks.