Many owners avoid popping the hood of their vehicle like a plague until it's unavoidable - typically when smoke is pouring out of it. Even if there's nothing wrong with your car, getting or performing your own tune-up is a smart idea that can help avoid major problems down the line.

The term "tune-up" is actually rather outdated when it comes to modern cars. On older vehicles, just about every system could be tweaked and controlled to eke out the best performance in a vehicle. Nowadays, most of the critical engine tasks are electronically controlled by the car's onboard computer. The vehicle can tell when something is amiss and often adjust in order to compensate. With that in mind, owners still need to perform a tune-up from time to time in order to ensure everything's running right.

While what goes into a tune-up may vary from mechanic to mechanic, most agree the spark plugs are a critical component of any tune-up. Spark plugs are responsible for igniting the fuel mixture in the engine, and it's important they fire at the correct intervals. Thus, they need replacing every now and again. Replacing spark plugs is a quick and easy job just about any amateur mechanic should be able to handle. The key thing to remember here is to not cross any of the wires when replacing the plugs. The best way to do a full spark plug replacement is simply one at a time - pop the old one off, put the new one on, and then move to the next plug.

Filters are another major aspect of any tune-up. No matter what aspect of the car a filter is responsible for, the idea behind the filter is the same - keep contaminants from getting somewhere they're not suppsoed to be. The problem with this is those contaminants attach themselves to the filter. Over time, they'll clog up the filter and prevent whatever it is that's supposed to be getting through from reaching its destination. A tune-up will likely replace the air, fuel and breather filters, along with the PCV valve.

A big part of the tune-up is preventative maintenance. It's unlikely every part of the vehicle will need service, unless it's been quite a long time since your last tune-up. But while the hood is popped, it's a good chance to check the other systems. Does the car need an oil change? Are all of the fluids where they're supposed to be? Do the belts show any signs of wear and tear? How's the battery voltage? While replacing or fixing these parts may not be included in the cost of a tune-up at many garages, the mechanics will usually let you know if something needs your attention.

If you're getting a tune-up at a garage, it's best to go over everything that will be included in the service in advance. Many shops will throw in a free oil change, offer to top up all your fluids, or perhaps even clean the fuel injectors.

Obviously, if you're performing your own maintenance, it will be at your discretion what aspects of the car need attention. It's a good idea to pop the hood and look at everything before you head to the auto parts store. That way, you can pick up everything you'll need for the tune-up in one trip and save yourself some time.